<PAGE>   1
                                                                   Exhibit 10.98

                           NASSAU DEVELOPMENT COMPANY



                                    "LESSOR"



                                       AND



                            JOHNSON ENGINEERING INC.



                                    "LESSEE"





<PAGE>   2
<TABLE>
<CAPTION>
                                TABLE OF CONTENTS

<S>                                                                                                      <C>
LESSOR AND LESSEE........................................................................................1
I.A        LEASED PREMISES...............................................................................1
II.A       TERM..........................................................................................1
II.B       USE...........................................................................................1
II.C       BASE RENTAL RATE..............................................................................2
II.D       SECURITY DEPOSIT..............................................................................2
II.E       RENTAL ESCALATION.............................................................................2
II.F       BASIC COSTS FOR ESCALATION....................................................................3
II.G       PAYMENT OF RENT...............................................................................4
III.A      SERVICES TO BE FURNISHED BY LESSOR............................................................4
III.B      PEACEFUL ENJOYMENT............................................................................5
IV.A       PAYMENTS BY LESSEE............................................................................5
IV.B       REPAIRS BY LESSOR.............................................................................5
IV.C       REPAIRS BY LESSEE.............................................................................6
IV.D       CARE OF THE LEASED PREMISES...................................................................6
IV.E       ASSIGNMENT OR SUBLEASE........................................................................6
IV.F       ALTERATIONS, ADDITIONS AND IMPROVEMENTS.......................................................6
IV.G       LEGAL USE AND VIOLATIONS OF INSURANCE COVERAGE................................................7
IV.H       LAWS AND REGULATIONS; RULES OF BUILDING.......................................................7
IV.I       ENTRY FOR REPAIRS AND INSPECTION..............................................................7
IV.J       NUISANCE......................................................................................7
IV.K       ASSIGNMENT....................................................................................7
IV.L       DEFAULT.......................................................................................8
IV.M       WAIVER........................................................................................8
IV.N       BANKRUPTCY BY LESSEE..........................................................................9
IV.O       AD VALOREM TAXES..............................................................................9
IV.P       CASUALTY INSURANCE............................................................................9
IV.Q       INDEMNITY.....................................................................................9
V.A        CONDEMNATION AND LOSS OR DAMAGE..............................................................10
V.B        LESSOR'S LIEN FOR RENT.......................................................................10
V.C        ABANDONMENT..................................................................................11
V.D        HOLDING OVER.................................................................................11
V.E        FIRE CLAUSE..................................................................................11
V.F        ESTOPPEL CERTIFICATE.........................................................................12
V.G        ATTORNEY'S FEE...............................................................................12
V.H        ALTERATION...................................................................................12
V.I        WAIVER OF SUBROGATION RIGHTS.................................................................12
V.J        NOTICES......................................................................................13
V.K        LEGAL INTERPRETATION.........................................................................13
</TABLE>

                                       i
<PAGE>   3

                                LEASE AGREEMENT

THE STATE OF TEXAS

COUNTY OF HARRIS

LESSOR AND LESSEE

This Lease Agreement made and entered into on this the 19th day of February,
1998, between Nassau Development Company, "Lessor" whose address for purposes
hereof is 18100 Upper Bay Road, Suite A, Houston, Texas 77058, acting by and
through its duly authorized representative, and Johnson Engineering Inc.,
"Lessee" whose address in Houston, Texas, for purposes hereof is 18100 Upper Bay
Road, Suite 207, Houston, Texas 77058.


                              W I T N E S S E T H:

                                       I.

I.A      LEASED PREMISES

(1) Subject to and upon the terms, provisions and conditions hereinafter set
forth, and each in consideration of the duties, covenants and obligations of the
other hereunder, Lessor has leased, demised and rented to Lessee the following
described premises, suites 204, 207 and 220 (herein referred to as "Leased
Premises") which is a total of 3,952 rentable square feet, situated in B. XII,
the "Building," located at 18100 Upper Bay Road, Suite 207, Houston, Harris
County, Texas.

(2) The number of square feet of gross rentable area comprising the building of
which the Leased Premises are situated in shall be 24,148 square feet unless
enlarged or reduced by written amendment or addendum hereto.

                                      II.

II.A     TERM

Subject to and upon the terms and conditions set forth herein, or in any exhibit
or addendum hereto, this lease shall continue in force for a term of one year,
beginning on the 1st of March, 1998. This Lease will expire on February 28,
1999.

II.B     USE

The Leased Premises are to be used and occupied by Lessee solely for the
purposes of conducting its business of aerospace engineering. Provided, however,
that Lessee may



<PAGE>   4
not use the Leased Premises in such a way as to interfere with
the use and enjoyment of other tenants or which is otherwise inconsistent with
the terms of this Agreement.

II.C     BASE RENTAL RATE

The base rental shall be $9.60 per square foot per year ($.80 per square foot
per month) for each square foot of gross rentable area then being leased by
Lessee under the terms and provisions hereof. ($3,161.60 Dollars of Rent per
Month).

II.D     SECURITY DEPOSIT

[text cut off] Lessee shall timely discharge in full all its obligation under
this Agreement, the security deposit shall be returned to Lessee thirty (30)
days after the expiration of the term of this Agreement. In the event of
transfer of this Agreement by Lessor, Lessor shall have the right to transfer
the security deposit to the transferee in which event Lessor shall have no
further obligation to Lessee for return of the security deposit.

II.E     RENTAL ESCALATION

(1) The term "Lease Year," as used herein, shall mean the fiscal year ending
March 31 of the year in which this Lease Agreement is entered into and any
subsequent fiscal year(s) during the initial term hereof and any extensions or
renewals hereof. In any Lease Year in which the Basic Costs (as defined in
paragraph II.F below) for maintaining and operating the Building, of which the
leased premises are a part, exceed the amount of FIVE AND 00/100 Dollars ($5.00)
per square foot of rentable area then leased by Lessee for that year (the "Base
Stop"), Lessee shall pay as additional rent the amount equal to Lessee's
proportionate share of the amount of the Basic Costs that exceed the Base Stop.
Lessee's "proportionate share" of the amount of Basic Costs that exceed the Base
Stop shall be the same percentage of the amount of Basic Costs over the Base
Stop as is equal to the percentage which the gross rentable area then leased by
Lessee in the Building bears to the total gross rentable area contained in the
Building.

(2) Lessor may submit to Lessee, and Lessee agrees to pay, a bill or invoice as
frequently as each month for one-twelfth (1/12) of the estimated annual amount
as may be ascertained by Lessor to be due by Lessee under this Article.
Alternatively, Lessor may submit to Lessee (at Lessor's sole discretion), and
Lessee agrees to pay, a bill or invoice as frequently as each month for the
actual increase in Basic Costs over the amount of the Base Stop for that month
and any preceding months for which rental escalation is due under this Article.
In the event of such billing or invoicing as provided hereunder by Lessor,
Lessee agrees and covenants to pay such additional amount contemporaneously with
the Base Rental on the first day of each calendar month, monthly in advance.

(3) Following the close of each Lease Year, Lessor shall determine the Basic
Costs for such Lease Year and give written notice thereof to Lessee which notice
shall also contain or be accompanied by a computation of additional rental, if
any, paid by Lessee as above provided and the balance, if any, then owing by
Lessee. In the event a balance is owing

                                       2

<PAGE>   5
by Lessee, same shall be paid by Lessee within ten (10) days of such notice. In
the event the computation for such Lease Year reflects a negative balance, same
shall be refunded by Lessor to Lessee within ten (10) days of such notice
provided that in no event shall the rental to be paid by Lessee for the leased
premises during the term of this Lease Agreement, and any extensions or renewals
hereof, ever be less than the base rental stated in Paragraph II.C of this Lease
Agreement. Lessee shall receive no benefit for a decrease in Basic Costs or the
amount of Basic Costs below the Base Stop for any calendar or fiscal year, or
any part thereof, during the term of this Lease Agreement, or any extensions and
renewals thereof. For the last Lease Year, Lessee shall only pay for such Lease
Year that portion of its proportionate share of the amount of Basic Costs that
exceed the Base Stop as the number of calendar days in the last Lease Year that
this Lease Agreement is in effect bears to 365.

II.F     BASIC COSTS FOR ESCALATION

(1) "Basic Costs" as said term is used herein shall consist of the operating
expenses of the Building, which shall be computed on the accrual basis. All
operating expenses shall be determined in accordance with generally accepted
accounting principles which shall be consistently applied. The term "operating
expenses" as used herein shall mean all expenses, costs and disbursements (but
not replacement of capital investment items) of every kind and nature which
Lessor shall incur, pay or be obligated to pay because of or in connection with
the ownership, and/or operating of the Building, including, but not limited to,
the following:

    (a)           All expenses of employment of all employees engaged in
                  operation and maintenance of the Building including wages and
                  salaries, employer's Social Security taxes, unemployment taxes
                  or insurance, and any other taxes which may be levied on such
                  wages and salaries as well as the cost of disability and
                  hospitalization insurance and pension or retirement benefits
                  for such employees.

    (b)           All supplies and materials used in operation and maintenance
                  of the Building.

    (c)           Cost of utilities, except those billed directly to tenants,
                  including but not limited to water and power, heating,
                  lighting, air conditioning and ventilating the Building.

    (d)           Cost of all maintenance and service agreements on equipment,
                  including alarm service, janitorial service, landscaping,
                  window cleaning and elevator maintenance.

    (e)           Cost of casualty and liability insurance applicable to the
                  Building and Lessor's personal property used in connection
                  therewith.

    (f)           All taxes, assessments and governmental charges whether
                  federal, state, county or municipal, and whether they be by
                  taxing districts or authorities


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<PAGE>   6
                  presently taxing the Leased Premises or by others,
                  subsequently created or otherwise, and any other taxes and
                  assessments attributable to the Building or its operation
                  excluding, however, federal and state taxes on income.

    (g)           Cost of repairs and general maintenance. (The costs of repairs
                  and general maintenance shall exclude alterations attributable
                  solely to tenants of the Building other than Lessee.)

    (h)           Management fees not to exceed five (5%) percent of the base
                  rentals, rental escalations, tenant assessments and other
                  rents, costs, charges or expenses incurred, derived from or
                  associated with the Building.

    (i)           Accounting fees actually incurred by Lessor in operation of
                  the Building and determination of escalation charges.

    (j)           A reasonable amortization charge on account of any capital
                  expenditures incurred to effect a reduction in operating
                  expenses of the Building.

(2) Lessee at its expense shall have the right at all reasonable times to audit
Lessor's book and records relating to this lease for any year or years for which
additional rental payments become due.

II.G     PAYMENT OF RENT

(1) The annual base rent adjusted in accordance with any exhibits hereto, if
applicable, shall be due and payable in advance in twelve (12) equal monthly
installments on the first day of each calendar month during the initial term and
any extensions or renewals thereof, and Lessee hereby agrees to so pay such rent
to Lessor at Lessor's address as provided herein monthly in advance without
demand. Additional rental for Lessee's share of Lessor's increased costs in
accordance with the escalation formula shall be due and payable quarterly as
provided in II.E above.

                                      III.

III.A    SERVICES TO BE FURNISHED BY LESSOR

(1) Lessee shall pay for the electricity, gas and water utilized in operating
any and all facilities servicing the Leased Premises except as otherwise
provided herein.

(2) "Lessor shall furnish to Lessee, while occupying the premises:

         (a)    Hot and cold water at those points of supply provided for
                general use of other tenants in the Building, central heat and
                air conditioning in season, at such times as Lessor normally
                furnishes these services to other tenants in the Building, and
                at such temperatures and in such amounts as are considered by
                Lessor to be standard, such service on Saturdays, Sundays and
                legal holidays to be furnished only upon the request of Lessee,
                who


                                       4

<PAGE>   7
                shall bear the entire cost thereof; janitorial service on a
                five (5) day week basis, electric lighting service for all
                public areas and special service areas of the Building in the
                manner and to the extent deemed by Lessor to be standard; but
                failure by Lessor to any extent to furnish these defined
                services, or any cessation thereof, resulting from causes beyond
                the control of Lessor, shall not render Lessor liable in any
                respect for damages to either person or property, not be
                construed as an eviction of Lessee, nor work an abatement of
                rent, nor relieve Lessee from fulfillment of any covenant
                or agreement hereof.  Should any of the equipment or machinery
                break down, or for any cause cease to function properly, Lessor
                shall use reasonable diligence to repair same promptly, but
                Lessee shall have no claim for rebate of rent or damages on
                account of any interruptions in service occasioned thereby or
                resulting therefrom.

    (b)         Proper electrical facilities to furnish sufficient power for
                typewriters, voice writers, calculating machines and other
                machines of similar low electrical consumption; provided,
                however, that Lessee shall bear the utility costs, air
                conditioning costs and costs to install appropriate meters to
                determine such costs occasioned by electro-data processing
                machines and similar machines of high electrical consumption.
                Such machines of high electrical consumption shall not be
                installed within the Building without the prior written
                consent of Lessor.

III.B    PEACEFUL ENJOYMENT

(1) Lessee shall, any may peacefully have, hold and enjoy the Leased Premises,
subject to the other terms hereof, provided that Lessee pays the rental herein
recited and performs all of its covenants, duties and agreements herein
contained.

                                      IV.

IV.A     PAYMENTS BY LESSEE

(1) Lessee shall pay all rent and sums provided to be paid by lessor hereunder
at the times and in the manner herein provided.

IV.B     REPAIRS BY LESSOR

(1) Unless otherwise expressly stipulated herein, Lessor shall not be required
to make any improvements or repairs of any kind or character on the Leased
Premises during the term of this lease, except such repairs as may be required
for structural or exterior building maintenance including the painting of and
repairs to walls, floors, corridors, windows, and other structures and Building
equipment within and serving the Leased Premises, and such additional
maintenance as may be necessary because of damages by persons other than Lessee,
its invites, visitors, or anyone acting at its direction or on its behalf; and
as may be necessary solely because of the negligence of Lessor at its expense
beginning not more than fifteen (15) days after written notice thereof by
Lessee.


                                       5


<PAGE>   8
IV.C     REPAIRS BY LESSEE
(1) At its own cost and expense, Lessee shall repair or replace any damage or
injury done to the Building, or any part thereof, caused by Lessee, its agents,
employees, invitees, or visitors; provided however, if Lessee fails to make such
repairs or replacements promptly Lessor may, at its option, make such repairs or
replacements, and Lessee shall repay the costs thereof to Lessor on demand.
Lessee's indemnity obligation hereunder shall survive regardless of whether
Lessor is or is alleged to have caused or contributed to such damages through
its actions or interactions constituting negligence, or giving rise to strict
liability or statutory liability. Lessee agrees to keep the Leased Premises and
the Building free at all times of any mechanics' and materialmen's liens or
other liens arising from such repair or replacement, including, but not limited
to, posting bond to obtain a release of any such lien.

IV.D     CARE OF THE LEASED PREMISES

(1) Lessee shall not commit or allow any waste or damage to be committed on any
portion of the Leased Premises, and at the termination of this lease, by lapse
of time or otherwise, shall deliver up said Leased Premises to Lessor in as good
condition as at date of original possession by Lessee, ordinary wear and tear
excepted, and upon such termination of this lease, Lessor shall have the right
to re-enter and resume possession of the Leased Premises.

IV.E     ASSIGNMENT OR SUBLEASE

(1) Lessee shall not assign this Agreement or sublet the Leased Premises, or any
part thereof, without first obtaining the written consent of Lessor, however
Lessor agrees that it will not unreasonably or arbitrarily refuse to give such
permission or consent. No assignment or sublease of the Leased Premises shall be
valid or binding upon Lessor without such consent. In no event shall any such
assignment or sublease ever release Lessee from any obligation or liability
hereunder.

IV.F     ALTERATIONS, ADDITIONS AND IMPROVEMENTS

(1) Lessee shall not permit the Leased Premises to be used for any other purpose
than that stated in the use clause hereof, or make or allow to be made any
alterations [text cut off].

(2) The cost of any alterations, physical additions, or improvements shall be
borne and paid for solely by Lessee. Lessee agrees to keep the Leased Premises
and the Building free at all times of any mechanics' and materialmen's liens or
other liens arising from such alterations, physical additions or improvements
including, but not limited to, posting a bond to obtain a release of any such
lien. Lessor shall have the right to insist on adequate security by way of
insurance, bonding or other means, prior to any modification or alteration to
ensure compliance with this clause.


                                       6


<PAGE>   9
(3) Though all alterations, physical additions, or improvements made by Lessee
become the property of Lessor upon the termination of this lease, Lessor may
require that Lessee remove any or all alterations, additions, and improvements
installed or made by Lessee, and any other property placed on the premises by
Lessee, upon termination of the lease. In the event that Lessor requires Lessee
to remove all such alterations, additions, or improvements, Lessee shall bear
and pay the cost of such removal and shall repair any damage to the premises
caused by such removal and, absent express written permission of Lessor, to
restore the Leased Premises to its original condition, reasonable wear and tear
excepted.

IV.G     LEGAL USE AND VIOLATIONS OF INSURANCE COVERAGE

(1) Lessee shall not occupy or use, or permit any portion of the Leased Premises
to be occupied or used for any business or purpose which is unlawful,
disreputable or deemed to be extra-hazardous on account of fire, or permit
anything to be done which would in any way increase the rate of fire insurance
coverage on said Building and/or its contents.

IV.H     LAWS AND REGULATIONS; RULES OF BUILDING

(1) Lessee shall comply with all laws, ordinances, orders, rules and regulations
(state, federal, municipal and other agencies or bodies having any jurisdiction
thereof) relating to the use, condition or occupancy of the Leased Premises.
Lessee will comply with the rules of the Building adopted by Lessor which are
set forth as Exhibit "B" attached hereto to be initialed by the parties hereto,
and made a part hereof as fully as though set forth herein. Lessor shall have
the right at all times to change such rules and regulations or to amend them in
any reasonable manner as may be deemed advisable by Lessor for the safety, care
and cleanliness of the Leased Premises and for preservation of good order
therein, all of which changes and amendments will be sent by Lessor to Lessee in
writing and shall be thereafter carried out and observed by Lessee.

IV.I     ENTRY FOR REPAIRS AND INSPECTION

(1) Lessee shall permit Lessor, its agents or representatives to enter into and
upon any part of the Leased Premises at all reasonable hours to inspect same or
to clean, make repairs, alterations or additions thereto, as Lessor may deem
necessary or desirable, and Lessee shall not be entitled to any abatement or
reduction of rent by reason thereof.

IV.J     NUISANCE

(1) Lessee shall conduct its business and control its agents, employees,
invitees, and visitors in such manner as not to create any nuisance, or
interfere with, annoy or disturb any other tenant or Lessor in his operation of
the Building.

IV.K     ASSIGNMENT

(1) Lessor shall have the right to transfer and assign, in whole or in part, all
of its rights and


                                       7

<PAGE>   10
IV.L     DEFAULT

(1) Default on the part of the Lessee on paying said rent or any installment
thereof, as herein above provided, or default on Lessee's part in keeping or
performing any other term, covenant or condition of this lease such as to create
a breach thereof, shall authorize Lessor, at its sole option at any time after
such default, and after ten (10) days' written notice thereof to Lessee, to
declare this lease terminated, and upon the occurrence of any one or more of
such defaults, Lessor immediately, or at any time thereafter, may re-enter said
premises and remove all persons therefrom with or without legal process, and
without prejudice to any of its other legal rights. All claims for damages by
reason of such re-entry are expressly waived, as also are all claims for damages
by reason of any distress warrants or proceedings by way of sequestration which
Lessor may employ to recover said rents or possession of said premises;
provided, that Lessor shall not have the right to declare this lease terminated,
if, within ten (10) days after notice of any default, Lessee corrects the
default. Provided, however, that nothing herein shall restrict Lessor's rights
at law or equity to recover possession of the Leased Premises in the event of
multiple or repeated defaults, if consistent with the laws of this state.

(2) If Lessee defaults, Lessor shall be entitled to recover damages, including,
but not limited to, the total of all payments owing and unpaid as of the date of
the default, plus interest from the date due until paid at the greatest possible
non-usurious rate permitted by law (provided that if no usury statute shall
apply, past due rent and other payments shall bear interest at eighteen percent
(18%) per annum from the due date until paid); the costs of re-entry and
reletting, including without limitation the cost of any clean-up, reasonable
refurbishing, removal of Lessee's property and fixtures; other expenses caused
by Lessee's failure to quit the premises and leave the same in the required
condition; reasonable attorney's fees, including those incurred at trial and all
appeals; court costs; expert witness fees; advertising costs; and the difference
between (i) the annual base rent and all of Lessee's other obligations under
this lease and (ii) the actual annual base rent received by the landlord for the
period commencing with the date of the default and continuing through the
termination date. Damages shall survive the termination of this lease.

(3) Pursuit of any of the above-stated remedies by Lessor after a default by
Lessee shall not preclude pursuit of any other remedies provided in this lease
or applicable law, nor shall pursuit of any remedy constitute a forfeiture or
waiver of any payment due to Lessor.

IV.M     WAIVER

(1) Failure of Lessor to declare any default immediately upon occurrence
thereof, or delay in taking any action in connection therewith, shall not waive
such default, but Lessor shall have the right to declare any such default at any
time and take such action as might be lawful or authorized hereunder, either in
law or in equity.


                                       8


<PAGE>   11
IV.N     BANKRUPTCY BY LESSEE

(1) If voluntary bankruptcy proceedings are instituted by Lessee, or if Lessee
is adjudged a bankrupt, or if Lessee makes an assignment for the benefit of its
creditors, or if execution is issued against it, or if the interest of Lessee
hereunder passes by operation of law to any person other than Lessee, this lease
may, at the option of Lessor, be terminated by notice mailed by registered mail
and addressed to Lessee.

IV.O     AD VALOREM TAXES

(1) Lessor shall pay all ad valorem taxes which accrue against the Building
during the term of this lease. Lessee shall pay all ad valorem and similar taxes
levied upon or applicable to all personal property within the Leased Premises
and improvements in excess of building standard improvements.

IV.P     CASUALTY INSURANCE

(1) Lessor shall, at all times during the term of this lease, at its expense,
maintain a policy or policies of insurance issued by and binding upon some
insurance company, insuring the Building against loss or damage by fire,
explosion, or other hazards and contingencies for the full insurable value
thereof; provided that Lessor shall not insure any goods, property, or supplies
not owned by Lessor and/or covered lease which Lessee may bring or obtain upon
the Leased Premises, or any additional improvements which Lessee may construct
thereon. If the annual premiums charged Lessor for such casualty insurance
exceed the standard premium rates because the nature of Lessee's operation
results in extra-hazardous exposure, then Lessee shall upon receipt of
appropriate premium invoices reimburse Lessor for any such increases covering in
such premiums.

(2) Lessee shall be responsible for providing, at Lessee's own expense, all
insurance coverage necessary for protection against loss or damage from fire,
theft, or other casualty of Lessee's goods, furniture, leasehold improvements,
equipment, files and all other property placed in the Leased Premises and
liability insurance covering the Leased Premises.

IV.Q     INDEMNITY

(1) Lessee agrees to and does hereby hold harmless and unconditionally indemnify
Lessor, its agent, officers, directors, employees, representatives, invitees,
guests, and contractors (collectively referred to in this paragraph as "Lessor")
against and for all costs, expenses, claims, liability, and damages of every
nature (including, but not limited to attorney's fees, court costs, expert
witness fees and interest) which Lessor may at any time suffer, sustain or
become liable for by reason of any and all accidents, damages, losses or
injuries resulting in personal injury, death and/or loss of or damage to any
property in any manner arising from or related to, in whole or in part, the
presence, conduct of business or any act or omission of Lessee, its agents,
officers, directors, employees, representatives, invitees, guests, contractors
or any parties contracting or conducting business with Lessee. Lessee agrees to
hold Lessor harmless for such costs,


                                       9


<PAGE>   12
expenses, claims, liability and damages even if same arise or are alleged to
arise in any manner from any negligent act or omission of Lessor, or any act for
which Lessor could be liable under theories of strict or statutory liability,
excepting only that arising from the sole negligence of Lessor. In case of any
action or proceeding brought against Lessor by reason of such claim, Lessee,
upon notice from Lessor, shall defend such action or proceeding by counsel of
Lessor's own choosing.

                                       V.

V.A      CONDEMNATION AND LOSS OR DAMAGE

(1) If the Leased Premises shall be taken or condemned in whole or in part for
any public purpose, this lease shall, at the option of either party, forthwith
cease and terminate; and Lessor or Lessee shall not be liable or responsible to
each other for any loss or damage to any property or person occasioned by theft,
fire, act of God, public enemy, injunction, riot, strike, insurrection, war,
court order, requisition, or order of [text cut off on bottom of page]
governmental body or authority beyond the control of Lessor or Lessee, as the
case may be, or for any damage or inconvenience which may arise through repair
or alteration of any part of the Building, or failure to make any such repairs,
or from any cause whatever, unless caused solely by Lessor's or Lessee's gross
negligence, as the case may be, except as may be herein otherwise expressly
provided.

V.B      LESSOR'S LIEN FOR RENT

(1) Lessor shall have, at all times, a valid security interest to secure payment
of all rentals and other sums of money becoming due under this Lease from
Lessee, and to secure payment of any damages or loss that Lessor may suffer by
reason of the breach by Lessee of any covenant, agreement or condition contained
in this Lease, upon all goods, wares, equipment, fixtures, furniture, and other
personal property of Lessee which is now on the premises or which is placed on
the premises at some later date, and all proceeds from them. This property shall
not be removed from the premises without the consent of Lessor until all
arrearages in rent and all other sums of money then due to Lessor under this
Lease have been paid and discharged, and all the covenants, agreements, and
conditions of this Lease have been fully complied with and performed by Lessee.
Upon the occurrence of an event of* default by Lessee, Lessor may, in addition
to any other remedies provided in this Lease or by law, after giving reasonable
notice of the intent to take possession and giving an opportunity for a hearing
on the issue, enter upon the premises and take possession of any and all goods,
wares, equipment, fixtures, furniture, and other personal property of Lessee
situated on the premises without liability for trespass or conversion, and sell
the same at public or private sale, with or without having the property at the
sake, after giving Lessee reasonable notice of the time and place of

*    Upon the occurrence of an event of default by Lessee, Lessor shall not take
     possession of any government owned goods, wares, equipment, furniture, and
     other kinds of government property situated on the premises.


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<PAGE>   13
any public sale or of the time after which any private sale is to be made.
Lessor or its assigns may purchase any items to be sold at such a sale unless
they are prohibited from doing so by law. Unless otherwise provided by law, and
without intending to exclude any other manner of giving Lessee reasonable
notice, the requirement of reasonable notice shall be met if such notice is
given at least twenty-one (21) days before the time of the sale. The proceeds
from any such dispositions, less any and all expenses connected with the taking
of possession, holding and selling of the property (including reasonable
attorney's fees and other expenses), shall be applied as a credit against the
indebtedness secured by the security interest granted in this section. Any
surplus shall be paid to Lessee or as otherwise required by law; and Lessee
shall pay any deficiencies immediately. Upon request by Lessor, Lessee agrees to
execute and deliver to Lessor a financing statement in form sufficient to
perfect the security interest of Lessor in the aforementioned property and
proceeds under the provisions of the Uniform Commercial Code in force in the
State of Texas. The statutory lien for rent is not waived, the security interest
granted in this article being in additions and supplementary, to that lien.

V.C      ABANDONMENT

(1) In the event the Leased Premises are abandoned by Lessee, Lessor shall have
the right, but not the obligation, to relet same for the remainder of the term
provided for herein; and if the rent received through such reletting does not at
least equal the rent provided for herein, Lessee shall pay and satisfy any
deficiency between the amount of the rent so provided for and that received
through reletting, and, in addition thereto, shall pay all expenses incurred in
connection with any such reletting, including, but not limited to, the cost of
restoring premises to its prior condition. Nothing herein shall be construed as
in any way denying Lessor the right in the event of abandonment of said premises
or other breach of this Agreement by Lessee, to treat the same as an entire
breach and at Lessor's option immediately sue for the entire breach of this
Agreement and any and all damages which Lessor suffers thereby.

V.D      HOLDING OVER

(1) In the event of holding over by Lessee after expiration of termination of
this lease, Lessee shall pay as liquidated damages double rent on a per diem
basis, for the entire holdover period. No holding over by Lessee after the term
of this lease, either with or without consent and acquiescence of Lessor, shall
operate to extend the lease for a longer period than one (1) month; and any
holding over with the consent of Lessor in writing shall thereafter constitute
this lease a lease from month to month.

V.E      FIRE CLAUSE

(1) In the event of a fire in the Leased Premises, Lessee shall immediately give
notice thereof to Lessor, if the Leased Premises, through no fault or neglect of
Lessee, its agents, employees, invitees or visitors, shall be partially
destroyed by fire or other casualty so as to render the premises untenantable,
the rental herein shall cease thereafter until such time as the Leased Premises
are made tenantable by Lessor. In the event of the total destruction of the
Leased Premises without fault or neglect of Lessee, its agents,


                                       11

<PAGE>   14
employees, invitees or visitors, or if from such cause the same shall be so
damaged that Lessor shall decide not to rebuild, then all rent owed up to the
time of such destruction or termination shall be paid by Lessee and thenceforth
this lease shall cease and come to an end. If such damage is due to the fault or
neglect of Lessee, then all repairs shall be at Lessee's expense and there shall
be no abatement of rent. This obligation shall survive regardless of whether
Lessor is or is alleged to be concurrently negligent in connection with said
damages.

V.F      ESTOPPEL CERTIFICATE

(1) The Lessee agrees, at any time and from time to time, upon not less than
fifteen (15) business days' prior notice from the Lessor, to execute,
acknowledge and deliver to the Lessor a statement in writing (1) certifying that
this Lease is unmodified and in full force and effect (or if there have been
modifications, that this Lease is in full force and effect as modified and
stating the modifications); (2) stating the dates to which the rent and other
charges hereunder have been paid by the Lessee; (3) stating whether or not the
Lessee has knowledge that the Lessor is in default in the performance of any
covenant, agreement or condition contained in this Lease, and, if the Lessee has
knowledge of such a default, specifying each such default and (4) stating the
address to which notices to the Lessee shall be sent. Prior to the commencement
of or during the term of this Lease the Lessor shall, if requested by the
Lessee, deliver an estoppel certificate, in the substance and form described
above, relative to the status of this Lease and/or any ground lease, underlying
lease and/or mortgage encumbering the building, parking facility or land.

V.G      ATTORNEY'S FEE

(1) In the event Lessee makes default in the performance of any of the terms,
covenants, agreements or conditions contained in this lease such as to create a
breach thereof, and Lessor places the enforcement of this lease, or any part
thereof, or the collection of any rent due, or to become due hereunder, or
recovery of the possession of the Leased Premises in the hands of an attorney,
or files suit upon the same, Lessee agrees to pay Lessor its reasonable
attorney's fees, court costs, expert witness fees, and other costs of collection
as may be reasonably incurred by Lessor.

V.H      ALTERATION

(1) Lessor and Lessee agree that this Agreement supersedes all prior oral or
written agreements and may not be altered, changed or amended, except by an
instrument in writing, signed by both parties hereto.

V.I      WAIVER OF SUBROGATION RIGHTS

(1) Anything in this lease to the contrary notwithstanding, Lessee hereto hereby
waives any and all rights of recovery, claim, action or cause of action, against
Lessor, its agents, officers, employees and representatives for any loss or
damage that may occur to the premises hereby demised, or any improvements
thereto, or said Building of which the Leased Premises are a part, or any
improvements thereto, by reason of fire, the elements,


                                       12

<PAGE>   15
or any other cause which could be insured against under the terms of
standard fire and extended coverage or liability insurance policies, regardless
of cause or origin, including negligence, strict liability or statutory
liability of the Lessor, its agents, officers, employees and representatives.

V.J      NOTICES

(1) Any and all notices or other communication required or permitted by this
lease to be served on or given to either party to this lease by the other party
hereto shall be in writing and shall be deemed duly served and given when
personally delivered to the party to whom it is directed, or in lieu of such
personal service, when deposited in the United States mail, properly addressed,
with postage prepaid, to the parties at the following addresses:

                                     Lessor

Name:                          Michael L. Austin
Title:                         Property Manager
Company:                       Nassau Development Company
Address:                       18100 Upper Bay Road, Ste. A
                               Houston, TX 77058

                                     Lessee

Name:                          Scott Hanson
Title:                         Controller
Company:                       Johnson Engineering Inc.
Address:                       555 Forge River Road, Suite 150
                               Webster, Texas 77598

The addresses or other information provided above may be changed by either party
upon giving the other party seven (7) days written notice of such change. Such
notice shall identify this Lease Agreement and shall provide the information
specified above.

V.K      LEGAL INTERPRETATION

(1) This lease shall be governed by and construed in accordance with the laws of
the State of Texas. If any clause or provision of this lease is illegal, invalid
or unenforceable under present or future laws effective during the lease term or
any renewals or extensions thereof, then and in that event, it is the intention
of the parties hereto that the remainder of this lease shall not be affected
thereby, and it is also the intention of the parties to this lease that in lieu
of each clause or provision of this lease that is illegal, invalid or
unenforceable, there be added as a part of this lease a clause or provision as
may be possible and legal, valid and enforceable. The heading of the paragraphs
have been inserted for convenience only and are not to be considered in any way
in the construction or interpretation of this lease agreement.


                                       13

<PAGE>   16
This lease shall be binding upon and inure to the benefit of the heirs, personal
representatives and assigns of Lessor, and shall be binding upon and inure to
the benefit of the successors and assigns of Lessee. The pronouns of any gender
shall include the other genders, and either the singular or the plural shall
include the other.

The undersigned represent that they are authorized to sign this document, agree
to the foregoing and accept same on behalf of and as an act and deed of Lessor
and Lessee, as evidenced by their signatures below.

------------------------------              -----------------------------------
Lessor                                      Lessee

BY:                                         BY:
   ---------------------------                 --------------------------------
TITLE:                                      TITLE:
      ------------------------                    -----------------------------
DATE:                                       DATE:
     -------------------------                   ------------------------------


                                       14


<PAGE>   17
                           NASSAU DEVELOPMENT COMPANY



                                    "LESSOR"



                                       AND



                            JOHNSON ENGINEERING INC.



                                    "LESSEE"















<PAGE>   18
<TABLE>
<CAPTION>
                                TABLE OF CONTENTS
<S>                                                                                                     <C>
PARTIES..................................................................................................1
I.A        LEASED PREMISES...............................................................................1
II.A       TERM..........................................................................................1
II.B       USE...........................................................................................1
II.C       BASE RENTAL RATE..............................................................................2
II.D       SECURITY DEPOSIT..............................................................................2
II.E       RENTAL ESCALATION.............................................................................2
II.F       BASIC COSTS OF ESCALATION.....................................................................3
II.G       PAYMENT OF RENT...............................................................................4
III.A      SERVICES TO BE FURNISHED BY LESSOR............................................................4
III.B      PEACEFUL ENJOYMENT............................................................................5
IV.A       PAYMENTS BY LESSEE............................................................................5
IV.B       REPAIRS BY LESSOR.............................................................................5
IV.C       REPAIRS BY LESSEE.............................................................................6
IV.D       CARE OF LEASED PREMISES.......................................................................6
IV.E       ASSIGNMENT OR SUBLEASE........................................................................6
IV.F       ALTERATIONS, ADDITIONS, AND IMPROVEMENTS......................................................6
IV.G       LEGAL USE AND VIOLATIONS OF INSURANCE COVERAGE................................................7
IV.H       LAWS AND REGULATIONS; RULES OF BUILDING.......................................................7
IV.I       ENTRY FOR REPAIRS AND INSPECTION..............................................................7
IV.J       NUISANCE......................................................................................8
IV.K       ASSIGNMENT....................................................................................8
IV.L       DEFAULT.......................................................................................8
IV.M       WAIVER........................................................................................9
IV.N       BANKRUPTCY BY LESSEE..........................................................................9
IV.O       AD VALOREM TAXES..............................................................................9
IV.P       CASUALTY INSURANCE............................................................................9
IV.Q       INDEMNITY....................................................................................10
V.A        CONDEMNATION AND LOSS OR DAMAGE..............................................................10
V.B        LESSOR'S LIEN FOR RENT.......................................................................10
V.C        ABANDONMENT..................................................................................11
V.D        HOLDING OVER.................................................................................11
V.E        FIRE CLAUSE..................................................................................12
V.F        ESTOPPEL CERTIFICATE.........................................................................12
V.G        ATTORNEY'S FEE...............................................................................12
V.H        ALTERATION...................................................................................13
</TABLE>

                                       i


<PAGE>   19
                                 LEASE AGREEMENT


THE STATE OF TEXAS

COUNTY OF HARRIS

LESSOR AND LESSEE

This Lease Agreement made and entered into on this the 26th day of January,
1998, between Nassau Development Company, "Lessor" whose address for purposes
hereof is 18100 Upper Bay Road, Suite A, Houston, Texas 77058, acting by and
through its duly authorized representative, and Johnson Engineering Corporation,
"Lessee" whose address in Houston, Texas, for purposes hereof is 18100 Upper Bay
Road, Suite 208, Houston, Texas 77058.


                              W I T N E S S E T H:

                                       I.

I.A      LEASED PREMISES

(1) Subject to and upon the terms, provisions and conditions hereinafter set
forth, and each in consideration of the duties, covenants and obligations of the
other hereunder, Lessor has leased, demised and rented to Lessee the following
described premises (herein referred to as "Leased Premises") which is a total of
2,958 rentable square feet, situated in B.XII, the "Building", located at 18100
Upper Bay Road, Suite 208, Houston, Harris County, Texas.

(2) The number of square feet of gross rentable area comprising the building of
which the Leased Premises are situated in shall be 24,148 square feet unless
enlarged or reduced by written amendment or addendum hereto.

                                      II.

II.A     TERM

Subject to and upon the terms and conditions set forth herein, or in any exhibit
or addendum hereto, this lease shall continue in force for a term of six (6)
months, beginning on the 1st of February, 1998. This Lease will expire on July
31, 1998.

II.B     USE

The Leased Premises are to be used and occupied by Lessee solely for the
purposes of conducting its business of aerospace engineering. Provided, however,
that Lessee may not use the Leased Premises in such a way as to interfere with
the use and enjoyment of other tenants or which is otherwise inconsistent with
the terms of this Agreement.


<PAGE>   20
II.C     BASE RENTAL RATE

The base rental rate shall be $9.60 per square foot per year ($.80 per square
foot per month) for each square foot of gross rentable area then being leased by
Lessee under the terms and provisions hereof. ($2,366.40 Dollars of Rent per
Month).

II.D     SECURITY DEPOSIT

Lessee has deposited with Lessor the sum of TWO THOUSAND THREE HUNDRED SIXTY SIX
& 40/100 DOLLARS ($2,366.40) as security for the faithful performance by Lessee
of its obligations under this Lease Agreement. In the event Lessee defaults in
any of its obligations hereunder, it is agreed Lessor, at its option without
notice to Lessee may use, apply or retain the whole or any part of the funds so
deposited as security to the extent required to discharge any such obligation of
Lessee and in the event such sum shall be insufficient to discharge such
obligation, Lessee shall remain liable for the balance of any such sum remaining
after application of the security deposit. In the event Lessee shall timely
discharge in full all its obligation under this Agreement, the security deposit
shall be returned to Lessee thirty (30) days after the expiration of the term of
this Agreement. In the event of transfer of this Agreement by Lessor, Lessor
shall have the right to transfer the security deposit to the transferee in which
event Lessor shall have no further obligation to Lessee for return of the
security deposit.

II.E     RENTAL ESCALATION

(1) The term "Lease Year", as used herein, shall mean the fiscal year ending
March 31 of the year in which this Lease Agreement is entered into and any
subsequent fiscal year(s) during the initial term hereof and any extensions or
renewals hereof. In any Lease Year in which the Basic Costs (as defined in
paragraph II.F below) for maintaining and operating the Building, of which the
leased premises are a part, exceed the amount of FIVE AND XX/100 Dollars ($5.00)
per square foot of rentable area then leased by Lessee for that year (the "Base
Stop"), Lessee shall pay as additional rent the amount equal to Lessee's
proportionate share of the amount of the Basic Costs that exceed the Base Stop.
Lessee's "proportionate share" of the amount of Basic Costs that exceed the Base
Stop shall be the same percentage of the amount of Basic Costs over the Base
Stop as is equal to the percentage which the gross rentable area then leased by
Lessee in the Building bears to the total gross rentable area contained in the
Building.

(2) Lessor may submit to Lessee, and Lessee agrees to pay, a bill or invoice as
frequently as each month for one-twelfth (1/12) of the estimated annual amount
as may be ascertained by Lessor to be due by Lessee under this Article.
Alternatively, Lessor may submit to Lessee (at Lessor's sole discretion), and
Lessee agrees to pay, a bill or invoice as frequently as each month for the
actual increase in Basic Costs over the amount of the Base Stop for that month
and any preceding months for which rental escalation is due under this Article.
In the event of such billing or invoicing as provided hereunder by Lessor,
Lessee agrees, and covenants to pay such additional amount contemporaneously
with the Base Rental on the first day of each calendar month, monthly in
advance.


                                       2

<PAGE>   21
(3) Following the close of each Lease Year, Lessor shall determine the Basic
Costs for such Lease Year and give written notice thereof to Lessee which notice
shall also contain or be accompanied by a computation of additional rental, if
any, paid by Lessee as above provided and the balance, if any, then owing by
Lessee. In the event a balance is owing by Lessee, same shall be paid by Lessee
within ten (10) days of such notice. In the event the computation for such Lease
Year reflects a negative balance, same shall be refunded by Lessor to Lessee
within ten (10) days of such notice provided that in no event shall the rental
to be paid by Lessee for the leased premises during the term of this Lease
Agreement, and any extensions or renewals hereof, ever be less than the base
rental stated in Paragraph II.C of this Lease Agreement. Lessee shall receive no
benefit for a decrease in Basic Costs or the amount of Basic Costs below the
Base Stop for any calendar or fiscal year, or any part thereof, during the term
of this Lease Agreement, or any extensions and renewals thereof. For the last
Lease Year, Lessee shall only pay for such Lease Year that portion of its
proportionate share of the amount of Basic Costs that exceed the Base Stop as
the number of calendar days in the last Lease Year that this Lease Agreement is
in effect bears to 365.

II.F     BASIC COSTS FOR ESCALATION

(1) "Basic Costs as said term is used herein shall consist of the operating
expenses of the Building, which shall be computed on the accrual basis. All
operating expenses shall be determined in accordance with generally accepted
accounting principles which shall be consistently applied. The term "operating
expenses" as used herein shall mean all expenses, costs and disbursements (but
not replacement of capital investment items) of every kind and nature which
Lessor shall incur, pay or be obligated to pay because of or in connection with
the ownership, and/or operation of the Building, including, but not limited to,
the following:

    (a)          All expenses of employment of all employees engaged in
                 operation and maintenance of the Building including wages and
                 salaries, employer's Social Security taxes, unemployment taxes
                 or insurance, and any other taxes which may be levied on such
                 wages and salaries as well as the cost of disability and
                 hospitalization insurance and pension or retirement benefits
                 for such employees.

    (b)          All supplies and materials used in operation and maintenance of
                 the Building.

    (c)          Cost of utilities, except those billed directly to tenants,
                 including but not limited to water and power, heating,
                 lighting, air conditioning and ventilating the Building.

    (d)          Cost of all maintenance and service agreements on equipment,
                 including alarm service, janitorial service, landscaping,
                 window cleaning and elevator maintenance.


                                       3

<PAGE>   22
    (e)          Cost of casualty and liability insurance applicable to the
                 Building and Lessor's personal property used in connection
                 therewith.

    (f)          All taxes, assessments and governmental charges whether
                 federal, state, county or municipal, and whether they be by
                 taxing districts or authorities presently taxing the Leased
                 Premises or by others, subsequently created or otherwise, and
                 any other taxes and assessments attributable to the Building
                 or its operation excluding, however, federal and state taxes
                 on income.

    (g)          Cost of repairs and general maintenance (The costs of repairs
                 and general maintenance shall exclude alterations attributable
                 solely to tenants of the Building other than Lessee.)

    (h)          Management fees not to exceed five (5%) percent of the base
                 rentals, rental escalations, tenant assessments and other
                 rents, costs, charges or expenses incurred, derived from or
                 associated with the Building.

    (i)          Accounting fees actually incurred by Lessor in operation of
                 the Building and determination of escalation charges.

    (j)          A reasonable amortization charge on account of any capital
                 expenditures incurred to effect a reduction in operating
                 expenses of the Building.

(2) Lessee at its expense shall have the right at all reasonable times to audit
Lessor's book and records relating to this lease for any year or years for which
additional rental payments become due.

II.G     PAYMENT OF RENT

(1) The annual base rent adjusted in accordance, with any exhibits hereto, if
applicable, shall be due and payable in advance in twelve (12) equal monthly
installments on the first day of each calendar month during the initial term and
any extensions or renewals thereof, and Lessee hereby agrees to so pay such rent
to Lessor at Lessor's address, as provided herein monthly in advance without
demand. Additional rental for Lessee's share of Lessor's increased costs in
accordance with the escalation formula shall be due and payable quarterly as
provided in II.E above.

                                      III.

III.A    SERVICES TO BE FURNISHED BY LESSOR

(1) Lessee shall pay for the electricity, gas and water utilized in operating
any and all facilities serving the Leased Premises except as otherwise provided
herein.

(2)      "Lessor shall furnish to Lessee, while occupying the premises:

    (a)          Hot and cold water at those points of supply provided for
                 general use of other tenants in the Building, central heat and
                 air conditioning in season, at


                                       4

<PAGE>   23
               such times as Lessor normally furnishes these services to
               other tenants in the Building, and at such temperatures and in
               such amounts as are considered by Lessor to be standard, such
               service on Saturdays, Sundays and legal holidays to be furnished
               only upon the request of Lessee, who shall bear the entire cost
               thereof; janitorial service on a five (5) day week basis,
               electric lighting service for all public areas and special
               service areas of the Building in the manner and to the extent
               deemed by Lessor to be standard; but failure by Lessor to any
               extent to furnish these defined services, or any cessation
               thereof, resulting from causes beyond the control of Lessor,
               shall not render Lessor liable in any respect for damages to
               either person or property, nor be construed as an eviction of
               Lessee, nor work an abatement of rent, nor relieve Lessee from
               fulfillment of any covenant or agreement hereof. Should any of
               the equipment or machinery break down, or for any cause cease to
               function properly, Lessor shall use reasonable diligence to
               repair same promptly, but Lessee shall have no claim for rebate
               of rent or damages on account of any interruptions in service
               occasioned thereby or resulting therefrom.

    (b)        Proper electrical facilities to furnish sufficient power
               for typewriters, voice writers, calculating machines and other
               machines of similar low electrical consumption; provided,
               however, that Lessee shall bear the utility costs, air
               conditioning costs and costs to install appropriate meters to
               determine such costs occasioned by electro-data processing
               machines and similar machines of high electrical consumption.
               Such machines of high electrical consumption shall not be
               installed within the Building without the prior written consent
               of Lessor.

III.B    PEACEFUL ENJOYMENT

(1) Lessee shall, and may peacefully have, hold and enjoy the Leased Premises,
subject to the other terms hereof, provided that Lessee pays the rental herein
recited and performs all of its covenants, duties and agreements herein
contained.

                                      IV.

IV.A     PAYMENTS BY LESSEE
(1) Lessee shall pay all rent and sums provided to be paid by Lessor hereunder
at the times and in the manner herein provided.

IV.B     REPAIRS BY LESSOR

(1) Unless otherwise expressly stipulated herein, Lessor shall not be required
to make any improvements or repairs of any kind or character on the Leased
Premises during the term of this lease, except such repairs as may be required
for structural or exterior building maintenance including the painting of and
repairs to walls, floors, corridors, windows, and other structures and Building
equipment within and serving the Leased


                                       5

<PAGE>   24
Premises, and such additional maintenance as may be necessary because of
damages by persons other than Lessee, its invites, visitors, or anyone acting at
its direction or on its behalf, and as may be necessary solely because of the
negligence of Lessor at its expense beginning not more than fifteen (15) days
after written notice thereof by Lessee.

IV.C     REPAIRS BY LESSEE

(1) At its own cost and expense, Lessee shall repair or replace any damage or
injury done to the Building, or any part thereof, caused by Lessee, its agents,
employees, invitees, or visitors; provided, however, if Lessee fails to make
such repairs or replacements promptly Lessor may, at its option, make such
repairs or replacements, and Lessee shall repay the costs thereof to Lessor on
demand. Lessee's indemnity obligation hereunder shall survive regardless of
whether Lessor is or is alleged to have caused or contributed to such damages
through its actions or interactions constituting negligence, or giving rise to
strict liability or statutory liability. Lessee agrees to keep the Leased
Premises and the Building free at all times of any mechanics' and materialmen's
liens or other liens arising from such repair or replacement including, but not
limited to, posting bond to obtain a release of any such lien.

IV.D     CARE OF LEASED PREMISES

(1) Lessee shall not commit or allow any waste or damage to be committed on any
portion of the Leased Premises, and at the termination of this lease, by lapse
of time or otherwise, shall deliver up said Leased Premises to Lessor in as good
condition as at date of original possession by Lessee, ordinary wear and tear
excepted, and upon such termination of this lease, Lessor shall have the right
to re-enter and resume possession of the Leased Premises.

IV.E     ASSIGNMENT OR SUBLEASE

(1) Lessee shall not assign this Agreement or sublet the Leased Premises, or any
part thereof, without first obtaining the written consent of Lessor, however
Lessor agrees that it will not unreasonably or arbitrarily refuse to give such
permission or consent. No assignment or sublease of the Leased Premises shall be
valid or binding upon Lessor without such consent. In no event shall any such
assignment or sublease ever release Lessee from any obligation or liability
hereunder.

IV.F     ALTERATIONS, ADDITIONS, AND IMPROVEMENTS

(1) Lessee shall not permit the Leased Premises to be used for any other purpose
than that stated in the use clause hereof, or make or allow to be made any
alterations or physical additions in or to the Leased Premises without first
obtaining the written consent of the Lessor. Any and all alterations, physical
additions, or improvements, when made to the Leased Premises by Lessee, shall at
once become the property of Lessor and shall be surrendered to Lessor upon the
termination of this lease by lapse of time or otherwise; provided, however, this
clause shall not apply to moveable equipment or furniture owned by Lessee.


                                       6

<PAGE>   25

(2) The cost of any alterations, physical additions, or improvements shall be
borne and paid for solely by Lessee. Lessee agrees to keep the Leased Premises
and the Building free at all times of any mechanics' and materialmen's liens or
other liens arising from such alterations, physical additions or improvements
including, but not limited to, posting a bond to obtain a release of any such
lien. Lessor shall have the right to insist on adequate security by way of
insurance, bonding or other means, prior to any modification or alteration to
ensure compliance with this clause.

(3) Though all alterations, physical additions, or improvements made by Lessee
become the property of Lessor upon the termination of this lease, Lessor may
require that Lessee remove any or all alterations, additions, or improvements
installed or made by Lessee, and any other property placed on the premises by
Lessee, upon termination of the lease. In the event that Lessor requires Lessee
to remove all such alterations, additions, or, improvements, Lessee shall bear
and pay the cost of such removal and shall repair any damage to the premises
caused by such removal and, absent express written permission of Lessor, to
restore the Leased Premises to its original condition, reasonable wear and tear
excepted.

IV.G     LEGAL USE AND VIOLATIONS OF INSURANCE COVERAGE

(1) Lessee shall not occupy or use, or permit any portion of the Leased Premises
to be occupied or used for any business purpose which is unlawful, disreputable
or deemed to be extra-hazardous on account of fire, or permit anything to be
done which would in any way increase the rate of fire insurance coverage on said
Building and/or its contents.

IV.H     LAWS AND REGULATIONS; RULES OF BUILDING

(1) Lessee shall comply with all laws, ordinances, orders, rules and regulations
(state, federal, municipal and other agencies or bodies having any jurisdiction
thereof) relating to the use, condition or occupancy of the Leased Premises.
Lessee will comply with the rules of the Building adopted by Lessor which are
set forth as Exhibit "B" attached hereto to be initialed by the parties hereto,
and made a part hereof as fully as though set forth herein. Lessor shall have
the right at all times to change such rules and regulations or to amend them in
any reasonable manner as may be deemed advisable by Lessor for the safety, care
and cleanliness of the Leased Premises and for preservation of good order
therein, all of which changes and amendments Will be sent by Lessor to Lessee in
writing and shall be there after carried out and observed by Lessee.

IV.I     ENTRY FOR REPAIRS AND INSPECTION

(1) Lessee shall permit Lessor, its agents or representatives to enter into and
upon any part of the Leased Promises at all reasonable hours to inspect same or
to clean, make repairs, alterations or additions thereto, as Lessor may deem
necessary or desirable, and Lessee shall not be entitled to any abatement or
reduction of rent by reason thereof


                                       7

<PAGE>   26
IV.J     NUISANCE

(1) Lessee shall conduct its business and control its agents, employees,
invitees, and visitors in such manner as not to create any nuisance, or
interfere with, annoy or disturb any other tenant or Lessor in his operation of
the Building.

IV.K     ASSIGNMENT

(1) Lessor shall have the right to transfer and assign, in whole or in part, all
of its rights and obligations hereunder in the Building and property referred to
herein and Lease shall execute any estoppel certificate reasonably required in
connection therewith within fifteen (15) days of receipt of request for such
estoppel certificate, as further explained in Paragraph V.F.

IV.L     DEFAULT

(1) Default on the part of the Lessee on paying said rent or any installment
thereof, as hereinabove provided, or default on Lessee's in keeping or
performing any other term, covenant or condition of this lease such as to create
a breach thereof, shall authorize Lessor, at its sole option at any time after
such default, and after ten (10) days' written notice thereof to Lessee, to
declare this lease terminated, and upon the occurrence of any one or more of
such defaults, Lessor immediately, or at any time thereafter may re-enter said
premises and remove all persons therefrom with or without legal process, and
without prejudice to any of its other legal rights. All claims for damages by
reason of such re-entry are expressly waived, as also are all claims for damages
by reason of any distress warrants or proceedings by way or sequestration which
Lessor may employ to recover said rents or possession of said premises;
provided, that Lessor shall not have the right to declare this lease terminated
if within ten (10) days after notice of any default, Lessee corrects the
default. Provided, however, that nothing herein shall restrict Lessor's rights
at law or equity to recover possession of the Leased Premises in the event of
multiple or repeated defaults, if consistent with the laws of this state.

(2) If Lessee defaults, Lessor shall be entitled to recover damages, including,
but not limited to, the total of all payments owing and unpaid as of the date of
the default, plus interest from the date due until paid at the greatest possible
non-usurious rate permitted by law (provided that if no usury statute shall
apply, past due rent and other payments shall bear interest at eighteen percent
(18%) per annum from the due date until paid); the costs of re-entry and
reletting, including without limitation the cost of any clean-up, reasonable
refurbishing, removal of Lessee's property and fixtures; other expenses caused
by Lessee's failure to quit the premises and leave the same in the required
condition; reasonable attorney's fees, including those incurred at trial and all
appeals; court costs; expert witness fees; advertising costs; and the difference
between (i) the annual base rent and all of Lessee's other obligations under
this lease and (ii) the actual annual base rent received by the landlord for the
period commencing with the date of the default and continuing through the
termination date. Damages shall survive the termination of this lease.


                                       8

<PAGE>   27
(3) Pursuit of any of the above-stated remedies by Lessor after a default by
Lessee shall not preclude pursuit of any other remedies provided in this lease
or applicable law, nor shall pursuit of any remedy constitute a forfeiture or
waiver of any payment due to Lessor.

IV.M     WAIVER

(1) Failure of Lessor to declare any default immediately upon occurrence
thereof, or delay in taking any action in connection therewith, shall not waive
such default, but Lessor shall have the right to declare any such default at any
time and take such action as might be lawful or authorized hereunder, either in
law or in equity.

IV.N     BANKRUPTCY BY LESSEE

(1) If voluntary bankruptcy proceedings are instituted by Lessee, or if Lessee
is adjudged a bankrupt, or if Lessee makes an assignment for the benefit of its
creditors, or if execution is issued against it, or if the interest of Lessee
hereunder passes by operation of law to any person other than Lessee, this lease
may, at the option of Lessor, be terminated by notice mailed by registered mail
and addressed to Lessee.

IV.O     AD VALOREM TAXES

(1) Lessor shall pay all ad valorem taxes which accrue against the Building
during the term of this lease. Lessee shall pay all ad valorem and similar taxes
levied upon or applicable to all personal property within the Leased Premises
and improvements in excess of building standard improvements.

IV.P     CASUALTY INSURANCE

(1) Lessor shall, at all times during the term of this lease, at its expense,
maintain a policy or policies of insurance issued by and binding upon some
insurance company, insuring the Building against loss or damage by fire,
explosion, or other hazards and contingencies for the full insurable value
thereof, provided that Lessor shall not insure any goods, property, or supplies
not owned by Lessor and/or covered lease which lessee may bring or obtain upon
the Leased Premises, or any additional improvements which Lessee may construct
thereon. If the annual premiums charged Lessor for such casualty insurance
exceed the standard premium rates because the nature of Lessee's operation
results in extra-hazardous exposure, then Lessee shall upon receipt of
appropriate premium invoices reimburse Lessor for any such increases covering in
such premiums.

(2) Lessee shall be responsible for providing, at Lessee's own expense, all
insurance coverage necessary for protection against loss or damage from fire,
theft, or other casualty of Lessee's goods, furniture, leasehold improvements,
equipment, files, and all other property placed in the Leased Premises and
liability insurance covering the Leased Premises.


                                       9

<PAGE>   28
IV.Q     INDEMNITY

(1) Lessee agrees to and does hereby hold harmless and unconditionally indemnify
Lessor, its agents, officers, directors, employees, representatives, invitees,
guests, and contractors (collectively referred to in this paragraph as "Lessor")
against and for all costs, expenses, claims, liability, and damages of every
nature (including, but, not limited to attorney's fees, court costs, expert
witness fees and interest) which Lessor may at any time suffer, sustain or
become liable for by reason of any and all accidents, damages, losses or
injuries resulting in personal injury, death and/or loss of or damage to any
property in any manner arising from or related to, in whole or in part, the
presence, conduct of business or any act or omission of Lessee, its agents,
officers, directors, employees, representatives, invitees, guests, contractors
or any parties contracting or conducting business with Lessee. Lessee agrees to
hold Lessor harmless for such costs, expenses, claims, liability and damages
even if same arise or are alleged to arise in any manner from any negligent act
or omission of Lessor, or any act for which Lessor could be liable under
theories of strict or statutory liability, excepting only that arising from the
sole negligence of Lessor. In case of any action or proceeding brought against
Lessor by reason of such claim, Lessee, upon notice from Lessor, shall defend
such action or proceeding by counsel of Lessor's own choosing.

                                       V.

V.A      CONDEMNATION AND LOSS OR DAMAGE

(1) If the Leased Premises shall be taken or condemned in whole or in part for
any public purpose, this lease shall, at the option of either party, forthwith
cease and terminate; and Lessor or Lessee shall not be liable or responsible to
each other for any loss or damage to any property or person occasioned by theft,
fire, act of God, public enemy, injunction, riot, strike, insurrection, war,
court order, requisition or order of governmental body or authority beyond the
control of Lessor or Lessee, as the case may be, or for any damage or
inconvenience which may arise through repair or alteration of any part of the
Building, or failure to make any such repairs, or from any cause whatever,
unless caused solely by Lessor's or Lessee's gross negligence, as the case may
be, except as may be herein otherwise expressly provided.

V.B      LESSOR'S LIEN FOR RENT

(1) Lessor shall have at all times, a valid security interest to secure payment
of all rentals and other sums of money due under this Lease from Lessee, and to
secure payment of any damages or loss that Lessor may suffer by reason of the
breach by Lessee of any covenant, agreement or condition contained in this
Lease, upon all goods, wares, equipment, fixtures, furniture, and other personal
property of Lessee which is now on the premises or which is placed on the
premises at some later date, and all proceeds from them. This property shall not
be removed from the premises without the consent of Lessor until all arrearages
in rent and all other sums of money then due to Lessor under this Lease have
been paid and discharged, and all the covenants, agreements, and conditions of
this Lease have been fully complied with and performed by Lessee. Upon


                                       10

<PAGE>   29
the occurrence of an event of* default by Lessee, Lessor may, in addition to any
other remedies provided in this Lease or by law, after giving reasonable notice
of the intent to take possession and giving an opportunity for a hearing on the
issue, enter upon the premises and take possession of any and all goods, wares,
equipment, fixtures, furniture, and other personal property of Lessee situated
on the premises without liability for trespass or conversion, and sell the same
at public or private sale, with or without having the property at the sale,
after giving Lessee reasonable notice of the time and place of any public sale
or of the time after which any private sale is to be made. Lessor or its assigns
may purchase any items to be sold at such a sale unless they are prohibited from
doing so by law. Unless otherwise provided by law, and without intending to
exclude any other manner of giving Lessee reasonable notice, the requirement of
reasonable notice shall be met if such notice is given at least twenty-one (21)
days before the time of the sale. The proceeds from any such dispositions, less
any and all expenses connected with the taking of possession, holding and
selling of the property (including reasonable attorney's fees and other
expenses), shall be applied as a credit against the indebtedness secured by the
security interest granted in this section. Any surplus shall be paid to Lessee
or as otherwise required by law; and Lessee shall pay any deficiencies
immediately. Upon request by Lessor, Lessee agrees to execute and deliver to
Lessor a financing statement in form sufficient to perfect the security interest
of Lessor in the aforementioned property and proceeds under the provisions of
the Uniform Commercial Code in force in the State of Texas. The statutory lien
for rent is not waived, the security interest granted in this article being in
additions and supplementary, to that lien.

V.C      ABANDONMENT

(1) In the event the Leased Premises are abandoned by Lessee, Lessor shall have
the right, but not the obligation, to relet same for the remainder of the term
provided for herein; and if the rent received through such reletting does not at
least equal the rent provided for herein, Lessee shall pay and satisfy any
deficiency between the amount of the rent so provided for and that received
through reletting, and, in addition thereto, shall pay all expenses incurred in
connection with any such reletting including but not limited to the cost of
restoring premises to its prior condition. Nothing herein shall be construed as
in any way denying Lessor the right in the event of abandonment of said premises
or other breach of this Agreement by Lessee, to treat the same as an entire
breach and at Lessor's option immediately sue for the entire breach of this
Agreement and any and all damages which Lessor suffers thereby.

V.D      HOLDING OVER

(1) In the event of holding over by Lessee after expiration of termination of
this lease, Lessee shall pay as liquidated damages double rent on a per diem
basis, for the entire

*    Upon the occurrence of an event of default by Lessee, Lessor shall not take
     possession of any government owned goods, wares, equipment, furniture, and
     other kinds of government property situated on the premises.

                                       11

<PAGE>   30
holdover period. No holding over by Lessee after the term of this lease, either
with or without consent and acquiescence of Lessor, shall operate to extend the
lease for a longer period than one (1) month; and any holding over with the
consent of Lessor in writing shall thereafter constitute this lease a lease from
month to month.

V.E      FIRE CLAUSE

(I) In the event of a fire in the Leased Premises, Lessee shall immediately give
notice thereof to Lessor, if the Leased Premises, through no fault or neglect of
Lessee, its agents, employees, invitees or visitors, shall be partially
destroyed by fire or other casualty so as to render the premises untenantable,
the rental herein shall cease thereafter until such time as the Leased Premises
are made tenantable by Lessor. In the event of the total destruction of the
Leased Premises without fault or neglect of Lessee, its agents, employees,
invitees or visitors, or if from such cause the same shall be so damaged that
Lessor shall decide not to rebuild, then all rent owed up to the time of such
destruction or termination shall be paid by Lessee and thenceforth this lease
shall cease and come to an end. If such damage is due to the fault or neglect of
Lessee, then all repairs shall be at Lessee's expense and there shall be no
abatement of rent. This obligation shall survive regardless of whether Lessor is
or is alleged to be concurrently negligent in connection with said damages.

V.F      ESTOPPEL CERTIFICATE

(1) The Lessee agrees, at any time and from time to time, upon not less than
fifteen (15) business days' prior notice from the Lessor, to execute,
acknowledge and deliver to the Lessor a statement in writing (1) certifying that
this Lease is unmodified and in full force and effect (or if there have been
modifications, that this Lease is in full force and effect as modified and
stating the modifications); (2) stating the dates to which the rent and other
charges hereunder have been paid by the Lessee; (3) stating whether or not the
Lessee has knowledge that the Lessor is in default in the performance of any
covenant, agreement or condition contained in this Lease, and, if the Lessee has
knowledge of such a default specifying each such default; and (4) stating the
address to which notices to the Lessee shall be sent. Prior to the commencement
of or during the term of this Lease the Lessor shall, if requested by the
Lessee, deliver an estoppel certificate, in the substance and form described
above, relative to the status of this Lease and/or any ground lease, underlying
lease and/or mortgage encumbering the building, parking facility or land.

V.G      ATTORNEY'S FEE

(1) In the event Lessee makes default in the performance of any of the terms,
covenants, agreements or conditions contained in this lease such as to create a
breach thereof, and Lessor places the enforcement of this lease, or any part
thereof, or the collection of any rent due, or to become due hereunder, or
recovery of the possession of the Leased Premises in the hands of an attorney,
or files suit upon the same, Lessee agrees to pay Lessor its reasonable
attorney's fees, court costs, expert witness fees, and other costs of collection
as may be reasonably incurred by Lessor.


                                       12

<PAGE>   31
V.H      ALTERATION

(1) Lessor and Lessee agree that this Agreement supersedes all prior oral or
written agreements and may not be altered, changed or amended, except by an
instrument in writing, signed by both parties hereto.

This lease shall be binding upon and inure to the benefit of the heirs, personal
representatives and assigns of Lessor, and shall be binding upon and inure to
the benefit of the successors and assigns of Lessee. The pronouns of any gender
shall include the other genders, and either the singular or the plural shall
include the other.

The undersigned represent that they are authorized to sign this document, agree
to the foregoing and accept same on behalf of and as an act and deed of Lessor
and Lessee, as evidenced by their signatures below.

--------------------------                  -----------------------------------
Lessor                                      Lessee

BY:                                         BY:
  ------------------------                     --------------------------------
TITLE:                                      TITLE:
  ------------------------                       ------------------------------
DATE:                                       DATE:
    ---------------------                        ------------------------------


                                       13

<PAGE>   32
                       NASSAU DEVELOPMENT COMPANY "LESSOR"

                                       AND

                    JOHNSON ENGINEERING CORPORATION "LESSEE"

                                 STATE OF TEXAS

                                COUNTY OF HARRIS



This is an addendum to the above mentioned Lease Agreements whereby effective
August 1, 1999, the existing Leases are hereby merged to form a single Lease
(hereinafter becoming The Lease) with a master suite address of 18100 Upper Bay
Road, Suite 207, Houston, Harris County, Texas 77058; hereinafter the term
Leased Premises shall apply to all rentable area under lease by Lessor to
Lessee. The following Articles, are hereby amended to read as follows:

ARTICLE I.A. LEASED PREMISES:

1. Subject to and upon the terms, provisions and conditions hereinafter set
forth, and each in consideration of the duties, covenants and obligations of the
other hereunder, Lessor has leased, demised and rented to Lessee the following
described premises (hereinafter referred to as "Leased Premises") which is a
total of 6,910 rentable square feet, situated in B. XII, the "Building", located
at 18100 Upper Bay Road, Suite 207, Houston, Harris County, Texas 77058.

2. The number of square feet of gross rentable area comprising the building of
which the Leased Premises are situated shall be 24,148 square feet unless
enlarged or reduced by written amendment or addendum hereto.

ARTICLE II.A TERM:

Subject to and upon the terms and conditions set forth herein, or in any exhibit
or addendum hereto, this Lease shall continue in force for a term of one (1)
year, beginning on the 1st of August, 1999. The Lease will expire on July 31,
2000.

ARTICLE II.C BASE RENTAL RATE:

The base rental rate shall be $9.60 per square foot per year ($.80 per square
foot per month) for each square foot of gross rentable area then being leased by
Lessee under the terms and provisions hereof. The Rent due for the Leased
Premises is therefore $5,528.00 Dollars of Rent per Month.

Exhibit D.1 becomes an attachment to the Lease per this Lease Amendment.


<PAGE>   33
All other terms and conditions of the above mentioned lease shall remain the
same and enforced. The undersigned represents that they are authorized to sign
this document, agree to the foregoing and accept same on behalf of and as an act
and deed of Lessor and Lessee, as evidenced by their signatures below.



---------------------------                   ---------------------------------
LESSOR                                        LESSEE

BY:                                           BY:
   ------------------------                       -----------------------------
TITLE:                                        TITLE:
      ---------------------                         ---------------------------
DATE:                                         DATE:
     ----------------------                        ----------------------------


                                       2