EXHIBIT 10.13

          The following is a draft proposal and does not constitute a
          commitment on the part of the herein named Lessor to lease the
          subject premises to the herein named Lessee.  The Lessor reserves
          the right to change or withdraw this proposal without notice at
          any time prior to the execution by the Lessor of a mutually
          satisfactory lease agreement.

                         STANDARD FORM COMMERCIAL LEASE
                         ------------------------------
      1.  PARTIES           Ark-Les Corp., a Massachusetts corporation, 95
          (fill in)         Mill Street, P. O. Box 686, Stoughton, MA
                            02072-0686 . . . . . Continued in 22.A.1. of
                            the RIDER.

                            LESSOR, which expression shall include its
                            heirs, successors, and assigns where the
                            context so admits, does hereby lease to Rogal
                            America, Inc., a Massachusetts corporation, . .
                            . . CONTINUED IN 22.A.2. OF THE RIDER.

                            LESSEE, which expression shall include its
                            successors, executors, administrators, and
                            assigns where the context so admits, and the
                            LESSEE hereby leases the following described
                            premises:

      2.  PREMISES          Approx. 15,900 rentable sq.ft., including
          (fill in and      attributable common area, of office space on
          include, if       the second floor of the building at 51 Water
          applicable,       Street, Watertown, MA, as shown on the attached
          suite number,     PLAN as "Exhibit A".
          floor number,
          and square feet)  together with the right to use in common, with
                            others entitled thereto, the hallways,
                            stairways, and elevators, necessary for access
                            to said leased premises, and lavatories nearest
                            thereto.

                            Continued in 22.B. of the RIDER.
      3.  TERM              See 22.C. of the RIDER.
          (fill in)

      4.  RENT              The LESSEE shall pay to the LESSOR rent as
          (fill in)         specified in 22.D. of the RIDER.

      5.  SECURITY          Upon the execution of this lease, the LESSEE
          DEPOSIT           shall pay to the LESSOR the amount of $25,000.
          (fill in)         Twenty-Five Thousand dollars, which shall be
                            held as a security for the LESSEE's performance
                            as herein provided and refunded to the LESSEE
                            at the end of this lease subject to the
                            LESSEE's satisfactory compliance with the
                            conditions hereof.
     <PAGE>
      6.  RENT              Additional Rent as specified in 22.E.
          ADJUSTMENT
          (fill in)

      7.  UTILITIES         The LESSOR shall provide and LESSEE shall pay
          (fill in or       for all LESSEE's utilities, water and sewer use
          delete) and       charges, including heating fuel; electricity
          services          for air conditioning, lights and power.

                            LESSOR agrees to furnish reasonable heat to the
                            leased premises, the hallways, stairways,
                            elevators, and lavatories during normal
                            business hours on regular business days of the
                            heating season of each year, to furnish
                            elevator service and to light passageways and
                            stairways during business hours, all subject to
                            interruption due to any accident, to the making
                            of repairs, alterations or improvements, to
                            labor difficulties, to trouble in obtaining
                            fuel, electricity, service or supplies from the
                            sources from which they are usually obtained
                            for said building, or to any cause beyond the
                            LESSOR's control.

                            Continued in 22.F. of the RIDER.

      8.  USE OF LEASED     The LESSEE shall use the leased premises only
          PREMISES          for the purpose of office activities related to
          (fill in)         the conduct of its convention service business.

      9.  COMPLIANCE        The LESSEE acknowledges that no trade or
          WITH LAWS         occupation shall be conducted in the leased
                            premises or use made thereof which will be
                            unlawful, improper, noisy or offensive, or
                            contrary to any law or any municipal by-law or
                            ordinance in force in the city or town in which
                            the premises are situated.

     10.  FIRE INSURANCE    The LESSEE shall not permit any use of the
                            leased premises which will make voidable any
                            insurance on the property of which the leased
                            premises are a part, or on the contents of said
                            property or which shall be contrary to any law
                            or regulation from time to time established by
                            the New England Fire Insurance Rating
                            Association, or any similar body succeeding to
                            its powers.  The LESSEE shall on demand
                            reimburse the LESSOR, and all other tenants,
                            all extra insurance premiums caused by the
                            LESSEE's use of the premises.
     <PAGE>
     11.  MAINTENANCE       The LESSEE agrees to maintain the leased
          OF PREMISES       premises in the same condition as they are at
                            the commencement of the term or as they may be
                            put in during the term of this lease,
                            reasonable wear and tear, damage by fire and
                            other casualty only excepted, and whenever
                            necessary, to replace plate glass and other
                            glass therein, acknowledging that the leased
                            premises are now in good order and the glass
                            whole.  The LESSEE shall not permit the leased
                            premises to be overloaded, damaged, stripped,
                            or defaced, nor suffer any waste.  LESSEE shall
                            obtain written consent of LESSOR before
                            erecting any sign on the premises.

                            Continued in 22.H. of the RIDER.

     12.  ALTERATIONS       The LESSEE shall not make structural
          ADDITIONS         alterations or additions to the leased
                            premises, but may make non-structural
                            alterations provided the LESSOR consents
                            thereto in writing, which consent shall not be
                            unreasonably withheld or delayed.  All such
                            allowed alterations shall be at LESSEE's
                            expense and shall be in quality at least equal
                            to the present construction.  LESSEE shall not
                            permit any mechanics' liens, or similar liens,
                            to remain upon the leased premises for labor
                            and material furnished to LESSEE or claimed to
                            have been furnished to LESSEE in connection
                            with work of any character performed or claimed
                            to have been performed at the direction of
                            LESSEE and shall cause any such lien to be
                            released of record forthwith without cost to
                            LESSOR.  Any alterations or improvements made
                            by the LESSEE shall become the property of the
                            LESSOR at the termination of occupancy as
                            provided herein.

     13.  ASSIGNMENT        The LESSEE shall not assign or sublet the whole
          SUBLEASING         or any part of the leased premises without
                            LESSOR's prior written consent, which consent
                            shall not be unreasonably withheld or delayed.
                            Notwithstanding such consent, LESSEE shall
                            remain liable to LESSOR for the payment of all
                            rent and for the full performance of the
                            covenants and conditions of this lease.

     14.  SUBORDINATION     The lease shall be subject and subordinate to
                            any and all mortgages, deeds of trust and other
                            instruments in the nature of a mortgage, now or
                            at any time hereafter, a lien or liens on the
                            property of which the leased premises are a
                            part and the LESSEE shall, when requested,
     <PAGE>
                            promptly execute and deliver such written
                            instruments as shall be necessary to show the
                            subordination of this lease to said mortgages,
                            deeds of trust or other such instruments in the
                            nature of a mortgage, PROVIDED SUCH INSTRUMENTS
                            RECOGNIZE THE RIGHTS OF THE LESSEE HEREUNDER,
                            SO LONG AS LESSEE IS NOT IN DEFAULT OF THIS
                            LEASE.

     15.  LESSOR'S ACCESS   The LESSOR or agents of the LESSOR may, at
                            reasonable times, enter to view the leased
                            premises and may remove placards and signs not
                            approved and affixed as herein provided, and
                            make repairs and alterations as LESSOR should
                            elect to do and may show the leased premises to
                            others, and at any time within three (3) months
                            before the expiration of the term, may affix to
                            any suitable part of the leased premises a
                            notice for letting or selling the leased
                            premises or property of which the leased
                            premises are a part and keep the same so
                            affixed without hindrance or molestation.

     16.  INDEMNIFICATION   The LESSEE shall save the LESSOR harmless from
          AND LIABILITY     all loss and damage to Lessee's property
          (fill in)         occasioned by the use or escape of water or by
                            the bursting of pipes, as well as from any
                            claim or damage resulting from neglect in not
                            removing snow and ice from the roof of the
                            building or from the sidewalks bordering upon
                            the premises so leased, or by any nuisance made
                            or suffered on the leased premises, unless such
                            loss is caused by the neglect of the LESSOR.
                            The removal of snow and ice from the sidewalks
                            bordering upon the leased premises shall be the
                            Lessor's responsibility.

                            See 22.J. of the RIDER for Exterior Costs.

     17.  LESSEE'S          The LESSEE shall maintain with respect to the
          LIABILITY         leased premises and the property, of which the
          INSURANCE         leased premises are a part, comprehensive
          (fill in)         public liability insurance in the amount of
                            $1,000,000 with property damage insurance in
                            limits of $1,000,000.  In responsible companies
                            qualified to do business in Massachusetts and
                            in good standing therein insuring the LESSOR as
                            well as LESSEE against injury to persons or
                            damage to property as provided.  The LESSEE
                            shall deposit with the LESSOR certificates for
                            such insurance at or prior to the commencement
                            of the term, and thereafter within thirty (30)
                            days prior to the expiration of any such
                            policies.  All such insurance certificates
     <PAGE>
                            shall provide that such policies shall not be
                            cancelled without at least ten (10) days prior
                            written notice to each assured named therein.

     18.  FIRE, CASUALTY    Should a substantial portion of the lease
          EMINENT DOMAIN    premises, or of the property of which they are
                            a part, be substantially damaged by fire or
                            other casualty, or be taken by eminent domain,
                            the LESSOR may elect to terminate this lease.
                            When such fire, casualty, or taking renders the
                            leased premises substantially unsuitable for
                            their intended use, a just and proportionate
                            abatement of rent shall be made, and the LESSEE
                            may elect to terminate this lease if:

                            (a)  The LESSOR fails to give written notice
                                 within ten (10) business days of intention
                                 to restore leased premises, or
                            (b)  The LESSOR fails to restore the leased
                                 premises to a condition substantially
                                 suitable for their intended use within
                                 forty-five (45) days of said fire,
                                 casualty, or taking.

                            The LESSOR reserves, and the LESSEE grants to
                            the LESSOR, all rights which the LESSEE may
                            have for damages or injury to the leased
                            premises for any taking by eminent domain,
                            except for damage to the LESSEE's fixtures,
                            property, or equipment.

     19.  DEFAULT AND       In the event that:
          BANKRUPTCY        (a)  The LESSEE shall default in the payment of
                                 any installment of rent or other sum
                                 herein specified and such default shall
                                 continue for ten (10) days after written
                                 notice thereof; or
                            (b)  The LESSEE shall default in the observance
                                 or performance of any other of the
                                 LESSEE's covenants, agreements, or
                                 obligations hereunder and such default
                                 shall not be corrected within thirty (30)
                                 days after written notice thereof; or
                            (c)  The LESSEE shall be declared bankrupt or
                                 insolvent according to law, or, if any
                                 assignment shall be made of LESSEE's
                                 property for the benefit of creditors,

                            then the LESSOR shall have the right
                            thereafter, while such default continues, to
                            re-enter and take complete possession of the
                            leased premises, to declare the term of this
                            lease ended, and remove the LESSEE's effects,
                            without prejudice to any remedies which might
     <PAGE>
                            be otherwise used for arrears of rent or other
                            default.  The LESSEE shall indemnify the LESSOR
                            against all loss of rent and other payments
                            which the LESSOR may incur by reason of such
                            termination during the residue of the term.  If
                            the LESSEE shall default, after reasonable
                            notice thereof, in the observance or
                            performance of any conditions or covenants on
                            LESSEE's part to be observed or performed under
                            or by virtue of any of the provisions in any
                            article of this lease, the LESSOR, without
                            being under any obligation to do so and without
                            thereby waiving such default, may remedy such
                            default for the account and at the expense of
                            the LESSEE.  If the LESSOR makes any
                            expenditures or incurs any obligations for the
                            payment of money in connection therewith,
                            including but not limited to, reasonable
                            attorney's fees in instituting, prosecuting or
                            defending any action or proceeding, such sums
                            paid or obligations insured, with interest at
                            the rate of six (6) per cent per annum and
                            costs, shall be paid to the LESSOR by the
                            LESSEE as additional rent.  THE LESSOR SHALL
                            USE REASONABLE EFFORTS TO MITIGATE LESSEE'S
                            LIABILITY THROUGH RE-LEASING OF THE PREMISES.

     20.  NOTICE            Any notice from the LESSOR to the LESSEE
          (fill in)         relating to the leased premises or to the
                            occupancy thereof, shall be deemed duly served,
                            if left at the lease premises addressed to the
                            LESSEE, or, if mailed to the leased premises,
                            registered or certified mail, return receipt
                            requested, postage prepaid, addressed to the
                            LESSEE.  Any notice from the LESSEE to the
                            LESSOR relating to the leased premises or to
                            the occupancy thereof, shall be deemed duly
                            served, if mailed to the LESSOR by registered
                            or certified mail, return receipt requested,
                            postage prepaid, addressed to the LESSOR at
                            such address as the LESSOR may from time to
                            time advise in writing.  All rent and notices
                            shall be paid and sent to the LESSOR at 95 Mill
                            Street, P.O. Box 686, Stoughton, MA  02072-
                            0686.

     21.  SURRENDER         The LESSEE shall at the expiration or other
                            termination of this lease remove all LESSEE's
                            goods and effects from the leased premises,
                            (including, without hereby limiting the
                            generality of the foregoing, all signs and
                            lettering affixed or painted by the LESSEE,
                            either inside or outside the leased premises).
                            LESSEE shall deliver to the LESSOR the leased
     <PAGE>
                            premises and all keys, locks thereto, and other
                            fixtures connected therewith and all
                            alterations and additions made to or upon the
                            leased premises, in the same condition as they
                            were at the commencement of the term, or as
                            they were put in during the term hereof,
                            reasonable wear and tear and damage by fire or
                            other casualty only excepted.  In the event of
                            the LESSEE's failure to remove any of LESSEE's
                            property from the premises, LESSOR is hereby
                            authorized, without liability to LESSEE for
                            loss or damage thereto, and at the sole risk of
                            LESSEE, to remove and store any of the property
                            at LESSEE's expense, or to retain same under
                            LESSOR's control or to sell at public or
                            private sale, without notice any or all of the
                            property not so removed and to apply the net
                            proceeds of such sale to the payment of any sum
                            due hereunder, or to destroy such property.

     22.  OTHER PROVISION   It is also understood and agreed that the
                            attached RIDER, Exhibit A, Exhibit B, and
                            Exhibit C are parts of this lease.

     IN WITNESS WHEREOF, the LESSOR and LESSEE have hereunto set their
     hands and common seals this 20th day of December, 1996




                            /s/ Thomas C. Hooper
                            -----------------------------------------------
                            LESSOR  Ark-les Corp.



                            /s/  Andrew Rogal
                            -----------------------------------------------
                            LESSEE  Rogal America, Inc.
     <PAGE>
     RIDER TO LEASE, DATED ______________, 1996, BETWEEN ARK-LES CORP. AND
     ROGAL AMERICA, INC., FOR PREMISES AT 51 WATER STREET, WATERTOWN, MA:

     22.A.1   PARTIES (Continued):...as Prime Tenant for the property of
              which the premises are a part, under a lease with Norman E.
              MacNeil, Bruce M. MacNeil, and Helen E. Stamsell Noonan,
              Trustees of N-K Realty Trust (the "Owner"), under Declaration
              of Trust dated June 30, 1975 and filed with the Middlesex
              South Registry District of the Land Court as Document No.
              534166, as amended, as Lessor under a Lease dated June 1,
              1978, as amended by an Eleventh Amendment of Lease dated June
              21, 1995 (the "Master Lease").  See attachment Exhibit C for
              APPROVAL AND AGREEMENT OF OWNER.

     22.A.2   PARTIES (continued):...presently located at 313 Washington
              Street, Newton, MA 02158.  Lessor agrees to accept as a
              substitute Lessee and successor to Rogal a LLC (Limited
              Liability Company), certified by the Commonwealth of
              Massachusetts, provided that the capitalization of the new
              entity is comparable to that of Rogal, as detailed in
              financial statements tendered to the Lessor.  Such
              substitution shall not be considered an assignment.

     22.B.    PREMISES (continued): The Lessee shall engage a qualified
              general contractor to effect the "Buildout Plan and
              Specifications", attached hereto as Exhibit B.  The Lessor
              shall contribute up to $250,000 towards the cost of this
              buildout, payable to the contractor as set forth in Exhibit
              B.  The Lessee shall be responsible for paying any buildout
              costs in excess of $250,000.

              The Lessor shall be responsible for effecting certain other
              improvements in the lobby and common areas, also as set forth
              in Exhibit B.

              The common areas are for the access and convenience of the
              Lessee and others entitled thereto.  Under no circumstances
              shall the Lessee use these common areas for its operations or
              storage.

     22.C.    TERM:  The term of this lease shall be for approximately five
              years commencing on the later of February 1, 1997 or the
              Commencement Date (as hereinafter defined) and terminating on
              the last day of the 60th full month.  The Commencement Date
              shall be defined as the date on which the premises are
              substantially ready for occupancy and may be occupied by
              Lessee for its intended use, subject only to completion of
              so-called "punch list" items which Lessor shall complete
              within 30 days, and further provided that Lessor shall have
              obtained confirmation from the Building Inspector of the Town
              of Watertown that the leased premises may be occupied for its
              intended use.
     <PAGE>
              The Lessee shall have the right to extend this lease for an
              additional term of five years, by notice to the Lessor, as
              provided in 20, herein, not less than 12 months prior to the
              expiration of the initial term.

     22.D.    BASE RENT:  The Lessee shall pay to the Lessor Base Rent at
              the rate of $171,960 per year, $14,330. per month, payable in
              advance on the first day of each month.  Lessee shall pay the
              Base Rent for the first full month upon execution of this
              lease.  In the event the Commencement Date falls on other
              than the first day of a calendar month, the Bast Rent for
              such month shall be prorated for such fractional period.

              Should the Lessee exercise its extension privilege as set
              forth in 22.C., the Base Rent shall be $171,960. per year
              indexed annually, at the commencement of each year of the
              extension term, to reflect the increase in the CPI-U for
              September of the previous year over the CPI-U for September
              1996.  (CPI-U is the Consumer Price Index, All Urban
              Consumers, All Items, (1982-84 -- 100), Boston, Mass.,
              published by the Bureau of Labor Statistics.  Comparable data
              will be used if CPI-U is unavailable or inapplicable).

     22.D.    ADDITIONAL RENT:  Lessee shall pay to the Lessor Additional
              Rent representing Lessee's proportionate share (18.2%) of
              real estate taxes and property insurance allocable to the
              land and building of which the premises are a part.  This
              Additional Rent shall be paid in advance in 1/12 monthly
              installments on the first day of each month.  Initially, the
              installments are estimated at $1,310. per month, $15,720 per
              year.  At the end of each lease year, amounts due to or from
              Lessee shall be reconciled and paid after actual tax and
              insurance amounts are determined.  Estimates payable by
              Lessee may be revised from time to time by Lessor.

              The Lessee shall pay the Additional Rent for the first month
              upon the execution of this lease.

              Should the Lessee elect, at its own expense, to seek
              abatement of real estate taxes on the property of which the
              premises are a part, the Lessor shall execute any necessary
              documents, thus permitting Lessee to appeal in Lessor's name.

              The Lessor shall maintain an "all-risk" insurance policy on
              the property of which the premises are a part in the
              principal amount of at least $2,500,000.

     22.F.    UTILITIES (Continued):  Lessee shall pay Lessee's
              Proportionate Share (18.2%) of heating costs attributable to
              the Building, and 100% of all utilities and electrical costs
              attributable to the leased premises.  In those instances
              where it is not reasonably feasible to segregate utility
              costs, they shall be attributed to the Lessee on a pro rata
              (square footage basis) and reimbursed by Lessee within ten
     <PAGE>
              business days of receipt of a bill thereof.  (The Lessor
              shall provide the Lessee with a breakout of such utility
              attribution on at least an annual basis).

              Where such attribution does not fairly reflect actual usage,
              the parties shall agree upon an attribution based on
              engineering principles; or failing such agreement, install
              information meters (with the parties sharing the cost).

              The Lessor acknowledges that Lessee's normal business hours
              are to be 24 hours per day, seven days per week.

     22.G.    COMPLIANCE WITH LAWS (Continued):  The Lessee shall keep all
              employees working in the leased premises covered with
              Workers' Compensation Insurance.  Lessee shall be responsible
              for causing the leased premises and any work conducted
              therein to be in full compliance with the Occupational Safety
              and Health Act of 1970 and amendments thereto.

     22.H.    MAINTENANCE OF PREMISES (Continued):  The Lessor shall be
              responsible for roof and structural integrity of the
              building, and for repairs and replacements to the existing
              heating and plumbing systems, and for major repairs and
              replacements to the existing heating and air conditioning
              equipment servicing the leased premises which are not covered
              by a standard maintenance contract.  The Lessor shall
              maintain such a contract on the existing heating and air
              conditioning equipment servicing the building of which the
              premises are a part; the Lessee shall reimburse the Lessor
              for Lessee's pro rata cost thereof within ten days of receipt
              of a bill thereof.

              The Lessee shall be responsible for repairs and replacements
              to any air conditioning equipment Lessee may install, for
              replacing bulbs and ballasts in the lighting system, and
              other normal interior cleaning and maintenance of the leased
              premises.

              The Lessor shall be responsible for replacing broken window
              glass, unless such breakage results from the negligence of
              the Lessee.

              Subject to Zoning Laws of the Town of Watertown, and subject
              to Lessor's reasonable approval of final design and location,
              Lessee may install a sign on the front of the Building.  The
              Lessee shall obtain the written consent of the Lessor before
              erecting any sign in or on the Building.

     22.I.    PARKING:  The Lessee shall have the use of a minimum of 50
              parking spaces in the paved parking area, in common with
              others entitled thereto.  The Lessor shall also assign five
              parking spaces for Lessee's exclusive use near the front
              lobby.  If necessary, the Lessor shall provide tenants of the
              building with a "parking by sticker only" system.
     <PAGE>
     22.J.    MUTUAL COOPERATION:  The Lessee shall cooperate with the
              Lessor and other tenants of the building in such matters as
              security, elevator use, lavatory cleaning and supplies,
              parking and other mutual concerns.  The Lessor shall impose a
              reciprocal obligation on the other tenants by inclusion of
              similar language in any future lease agreements.  The Lessor
              may make reasonable regulations to insure fair treatment for
              the Lessee and other tenants in the implementation of this
              section.

     22.K.    ENVIRONMENTAL:  The Lessee will so conduct and operate its
              business within the leased premises as not to interfere in
              any way with the use and enjoyment by others of other
              portions of the same or neighboring buildings by reason of
              odors, smells, noise, pets, accumulation of garbage, or
              trash, vermin pests or other nuisance.  The Lessee agrees to
              maintain efficient and effective devices for preventing
              damage to or contamination of the premises from solvents,
              degreasers, cutting oils or other substances used within the
              premises or property of which the leased premises are part.
              No hazardous chemical substances or wastes of any sort shall
              be used, stored, or disposed of improperly within the
              premises or property of which the leased premises are part
              any time; and Lessee shall be solely responsible for any and
              all contamination, corrosion or other damage associated with
              the use, control or disposal of same by Lessee.

              The Lessee shall not cause or permit any hazardous material
              to be brought upon, kept, or used in or about the premises or
              property of which the leased premises are part by the Lessee,
              it contractors, or subcontractors, or their agents or
              employees, unless such hazardous material is reasonably
              necessary or useful to the Lessee's business, and will be
              kept, and stored in a manner that complies with all laws
              relations to any such hazardous material.  If the Lessee
              breaches the obligations stated in the preceding sentence, or
              if the presence of hazardous material on the premises or
              property of which the leased premises are part caused or
              permitted by Lessee results in contamination of the premises
              or property of which the leased premises are part, or if
              contamination of the premises or property of which the leased
              premises are part by hazardous material otherwise occurs for
              which the Lessee is legally liable to the Lessor for damage
              resulting therefrom, then the Lessee shall indemnify, defend
              and hold the Lessor harmless from any and all claims,
              judgments, damages, penalties, fines, costs, liabilities, or
              losses (including, without limitation, diminution in the
              value of the premises or property of which the leased
              premises are part, damages for loss or restriction of use of
              rentable or usable space of any amenity of the premises, or
              property of which the leased premises are part, damages
              arising from any adverse impact on marketing of space, and
              reasonable sums paid in settlement of claims, attorneys'
              fees, consultant fees, and expert fees) which arise during or
              after the lease term or as a result of such contamination.
              The indemnification of the Lessor by the Lessee includes,
              without limitation, costs incurred in connection with any
              investigation of site conditions or any clean up, remedial,
     <PAGE>
              removal, or restoration work required by federal, state, or
              local governmental agency or political subdivision because of
              hazardous material present in the soil or ground water on or
              under the premises or property of which the leased premises
              are part.  Without limiting the generality of the foregoing,
              if the presence of any hazardous material on the premises or
              property of which the leased premises are part caused or
              permitted by the Lessee results in any contamination of the
              premises or property of which the leased premises are part,
              the Lessee shall promptly take all actions at its sole
              expense as are necessary to return the premises or property
              of which the leased premises are part to the condition
              existing prior to the introduction of any such hazardous
              material to the premises or property of which the leased
              premises are part; provided that the Lessor's approval of
              such action shall be first obtained, which approval shall not
              be unreasonably be withheld so long as such actions would not
              potentially have any material adverse long or short term
              effect on the premises or property of which the leased
              premises are part.  The foregoing shall survive the
              expiration or early termination of this lease.

              Lessee shall not be held responsible for any claims resulting
              from any hazardous material present in the leased premises,
              the Building, or the property of which the leased premises
              are part, introduced to such location prior to the lease
              term.

              Hazardous material is defined as any hazardous or toxic
              substance, material, or waste including, but not limited to,
              those substances, materials, and wastes listed in the United
              States Department Of Transportation Materials Table (49
              C.F.R. 172.101) or by the Environmental Protection Agency as
              Hazardous Substances (40 C.F.R. Part 302) and amendments
              thereto, or such substances, materials, and wastes that are
              or have become regulated under any federal, state, or local
              law, ordinance, or regulation including but not limited to,
              the Resource Conservation and Recovery Act, The Toxic
              Substances Control Act, The Comprehensive Environmental
              Response Compensation and Liability Act ("CERCLA" or
              Superfund"), The Clean Air Act, and The Clean Water Act, or
              the Massachusetts Oil and Hazardous Material Release
              Prevention and Response Act, M.G.L. c.21E, the Massachusetts
              Hazardous Waste Management Act, M.G.L. c.21C., and
              regulations promulgated under such laws and acts.

              The Lessor agrees that it will use its best efforts to
              enforce similar language in the leases of other tenants of
              the property of which the premises are a part.
     <PAGE>
     22.L.    FIRE PREVENTION:  The Lessee agrees to use every reasonable
              precaution against fire; and to provide and maintain
              approved, labeled fire extinguishes, emergency, lighting
              equipment, exit signs, and to complete any other
              modifications within the leased premises as are required or
              recommended by the Insurance Services Office (or successor
              organization), OSHA, local fire department, or any similar
              body.

     22.M.    RUBBISH DISPOSAL:  The Lessee shall be responsible for
              arranging and paying for its own trash removal service.

     22.N.    INTERIOR COSTS:  The Lessee shall reimburse the Lessor for
              its pro rata share of the cost of cleaning, maintaining, and
              lighting the lobby, hallways, stairways, elevator, and other
              common areas (the "Interior Costs") of the Building within
              ten business days of receipt of a bill therefor.  Lessee's
              pro rata share is defined as its percentage of gross rentable
              area having beneficial use of said common areas.  The
              Interior Costs shall not include the cost of capital
              improvements, nor shall they include the cost of upgrading
              the common areas of the Building.

              Lessee shall contract for daily morning cleaning and stocking
              of the common restrooms on the second floor.

     22.O.    EXTERIOR COSTS:  The Lessee shall reimburse the Lessor
              Lessee's Proportionate Share (18.2%) of the reasonable cost
              of landscaping, snow plowing and removal, parking lot
              cleaning and lighting, within ten business days of receipt of
              a bill therefor.

     22.P.    NOTICE OF LEASE:  The Lessor shall provide the Lessee with a
              so-called "Notice of Lease", in statutory form, suitable for
              recording at the Registry of Deeds.

     22.Q.    QUIET ENJOYMENT:  Lessor covenants that so long as the Lessee
              pays the rent and any other sums due, and performs all of its
              obligations hereunder, Lessee may peacefully and quietly
              have, hold and enjoy the premises throughout the term without
              undue interference from Lessor, its employees, agents, or
              contractors.

     22.R.    SOLVENT ODOR:  The Lessor shall take all reasonable measures
              to enforce the provisions of the lease with Mount Auburn
              Press restricting the use of so-called power cleaning
              solvents to its one story building section and for the proper
              ventilation of said section (continuous maintenance of a
              negative air pressure differential therein).

     22.S.    AVAILABLE SPACE:  The Lessor shall notify the Lessee of any
              space availability within the building; and shall not enter
              into a lease agreement for such space with a third party
              within five business days following such notice.
     <PAGE>
                                    EXHIBIT B

                         BUILDOUT PLAN & SPECIFICATIONS

     Subsequent to the execution of this lease, the Lessee shall submit to
     the Lessor, for the Lessor's approval, not to be unreasonably withheld
     or delayed, a "Buildout Plan & Specifications", detailing the
     improvements to be effected by the Lessee's general contractor,
     pursuant to Section 22.B. herein.

     The Lessee shall provide the Lessor a true and complete copy of the
     Lessee's contract with its general contractor, and of the schedule for
     progress payments to said contractor.

     The Lessee shall make a co-payment to each progress payment in the
     proportion of its total contribution of $250,000 to the estimated
     total cost of the contractor's work.

     The Lessor, at its expense, shall be responsible for improving the
     first floor lobby and other common areas to a level consistent with
     the premises occupied by the Lessee and other tenants of the building.
     In general, these improvements shall include acoustical ceilings,
     painted drywall (or wall covering), carpeting or other suitable floor
     covering.
     <PAGE>
                                    EXHIBIT C

                         APPROVAL AND AGREEMENT OF OWNER

     The Owner of the property of which the leased premises are part,
     hereby authorized Ark-Les Corp., its tenant under the Master Lease, to
     enter into this lease as Lessor.  The owner agrees that for as long as
     the Lessee is not in default beyond applicable grace or cure periods
     in the payment of rent or in the performance of the covenants or
     conditions of this lease, the Lessee's possession and occupancy of the
     leased premises and the Lessee's rights and privileges under this
     lease or extension thereof shall not be diminished or interfered with
     by Owner.

     The Owner further agrees that if the Master Lease is terminated,
     expires, or is not renewed and Lessee is not in default under the
     lease beyond applicable grace or cure periods, the Owner will
     recognize the Lessee's possession and occupancy under all terms of
     this lease.  The provisions of this Section shall bind the heirs,
     successors, and assigns of the Owner, as well as subsequent owners of
     the Building.

                                            Owner:  N-K Realty Trust

                                            _______________________________

                                            Name: _________________________

                                            Title: ________________________

                                            Date: _________________________
     <PAGE>
     [Not presented here is a diagram of the floor plan of the premises
     with the following notation:  "Note:  Space Plan Still In Process"]