PROMISSORY NOTE
                                                  March 17, 1997
$2,500,000 Maximum                                Roanoke, Virginia


     FOR VALUE RECEIVED, the undersigned, ETS INTERNATIONAL, INC., a
Virginia corporation ("Maker"), promises to pay to the order of THOMAS W.
MARMON, as Trustee of the THOMAS W. MARMON TRUST ("Payee"), the principal
amount equal to the aggregate amount of advances made by Payee to Maker
hereunder, which advances shall not exceed Two Million Five Hundred Thousand
Dollars ($2,500,000), together with interest at the rate of Twenty-Five
Thousand Dollars ($25,000) per month, regardless of the principal balance
from time to time outstanding.

     Maker shall make monthly interest payments to Payee of $25,000 in
installments commencing April 17, 1997, and on the 17th day of each month
thereafter until March 17, 1999, at which time the remaining balance of
principal and interest shall be paid in full; provided, however, that Payee
shall have the option to call this Note in full at any time upon sixty (60)
days written notice (i.e., Payee has the option to accelerate the entire
principal and interest owing and demand payment in full upon sixty (60) days
written notice).  The Maker reserves the right to pre-pay this Note at any
time upon sixty (60) days written notice to Payee.

     Late Charge.  If any installment of principal or interest is not paid
within ten (10) days of its due date, Maker will forthwith pay to the holder
of this Note a late charge in an amount equal to five percent (5%) of the
past due payment.  This is in addition to the holder's other rights and
remedies for default in payment of an installment of interest when due. 
Maker will pay this late charge promptly, but only once on each late payment.

     Security.  This Note and all obligations of Maker hereunder are secured
by certain security agreements and a guaranty of even date herewith, and any
and all security agreements, guaranties, mortgages, pledge agreements,
assignments, and all other agreements and instruments heretofore or hereafter
given by Maker or any third party to Payee ("Security Documents"), including,
but not limited to, Security Documents given in connection with or referred
to in any prior promissory notes given to Payee by any Maker and Security
Documents that secure any present or future guaranty of all or part of the
indebtedness evidenced by this Note.  Payee shall have all of the rights and
powers set forth in the Security Documents and in any other written
agreements heretofore or hereafter given to Payee by Maker, as though they
were fully set forth herein.  As additional security for the payment of
Maker's obligations under this Note, Maker grants to Payee a security
interest in all tangible and intangible property of Maker now or hereafter in
the possession of Payee.

     Default and Acceleration.  Each of the following shall be an event of
default under this Note: (a) if default occurs in the payment of any
installment of principal or interest hereunder or of any late charge or out-
of-pocket expense at any time owing to Payee under this Note or in the
payment of any other indebtedness or obligation now or hereafter owing by
Maker to Payee, as and when the same shall be or become due and payable and
such failure shall continue unremedied for a period of ten (10) days; (b) if
default occurs in the performance of any other obligation to Payee under this
Note or any Security Document or any other agreement heretofore or hereafter
entered into between Maker and Payee or if there occurs any other event of
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default under any Security Document or any such other agreement, and any such
default shall continue unremedied for a period of ten (10) days after the
sending of written notice of such default to Maker; (c) if any warranty or
representation heretofore or hereafter made to Payee by Maker or any
guarantor of all or part of the Indebtedness evidenced by this Note
("Guarantor"), in any Security Document or in any financial statement or
other document given to Payee in connection with this Note, shall have been
false in any material respect; (d) if Maker or any Guarantor, shall dissolve,
become insolvent, or make an assignment for the benefit of creditors; (e) if
any guaranty that now or hereafter secures payment of all or any part of the
indebtedness evidenced by this Note shall be terminated or limited for any
reason without the written consent or agreement of the holder of this Note;
(f) if any part of the principal or interest of, or any other payment of
money due under, any indebtedness for borrowed money of the Maker, including
without limitation any indebtedness to banks or other financial institutions,
is not paid when due or within any grace period; (g) if any indebtedness of
Maker (including without limitation any indebtedness to banks or other
financial institutions) becomes or is declared to be due and payable prior to
the stated maturity thereof as a result of any default or event of default
occurring with respect thereto; or (h) if at any time the holder of this Note
for any reason shall in good faith believe that the prospect of payment or
performance of this Note or any other indebtedness or obligation of Maker to
the holder is impaired.  Upon the occurrence of any event of default, all or
any part of the indebtedness evidenced hereby and all or any part of all
other indebtedness and obligations then owing by Maker to the holder shall,
at the option of the holder, become immediately due and payable without
notice or demand.  If a voluntary or involuntary case in bankruptcy,
receivership, or insolvency shall at any time be instituted by or against
Maker or any Guarantor and, in the case of an involuntary action, such action
is not discharged within thirty (30) days thereafter, or if any levy, writ of
attachment, garnishment, execution, or similar process shall be issued
against or placed upon any property of Maker or Guarantor, then all such
indebtedness shall automatically become immediately due and payable.  All or
any part of the indebtedness' evidenced hereby also may become, or may be
declared to be, immediately due and payable under the terms and conditions
contained in any Security Document.

     Place and Application of Payments.  Each payment upon this Note shall
be made to Payee at the following address: Thomas W. Marmon as Trustee of the
Thomas W. Marmon Trust, c/o Ceres Corporation, 4390 Airwest Drive SE, Grand
Rapids, Michigan 49512 or at such other place as the holder hereof may direct
in writing.  Any payment upon this Note shall be applied first to any
expenses (including expenses of collection) then due and payable to Payee
hereunder, then to any unpaid late charges, then to any accrued and unpaid
interest hereunder, and then to the unpaid principal balance.  If Maker at
any time owes the holder of this Note any indebtedness or obligation in
addition to the indebtedness evidenced by this Note, and if any indebtedness
owed by Maker to the holder is then in default, Maker shall have no right to
direct or designate the particular indebtedness or obligation upon which any
payment made by, or collected from, Maker or from any Guarantor or other
security shall be applied.  Maker hereby waives any such right and agrees
that the manner of application of any such payment, as between or among such
indebtedness and obligations, shall be determined solely by the holder.

     Setoff.  The holder of this Note shall have the right at any time to
set off any indebtedness that the holder then owes to Maker against any
indebtedness evidenced by this Note that is then due and payable.
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     Remedies.  The holder of this Note shall have all rights and remedies
provided by law and by agreement of Maker.  Any requirement of reasonable
notice with respect to any sale or other disposition of collateral shall be
met if the holder sends the notice at least 5 days prior to the date of sale
or other disposition.  Maker agrees to pay any and all expenses, including
reasonable attorney fees and legal expenses, paid or incurred by the holder
in protecting and enforcing the rights of and obligations to the holder under
any provision of this Note or any Security Document.

     Environmental Compliance.  Maker represents and warrants to, and agrees
with, Payee that: (a) none of Maker's real or personal property is, and Maker
will not permit it to become, unlawfully contaminated by any substance that
is now or hereafter regulated by or subject to any present or future law or
regulation that establishes liability for the removal or clean-up of, or
damage caused by, any environmental contamination; (b) Maker's operations,
activities, and real and personal properties are, and Maker shall cause them
to continue to be, in compliance with each such law and regulation in all
material respects; (c) if the indebtedness evidenced by this Note is not paid
at maturity, then at any time thereafter the holder of this Note may, but
shall not be obligated to, conduct or obtain an environmental investigation
or audit of any or all of Maker's properties, and Maker shall reimburse the
holder for all costs and expenses incurred by the holder in connection with
the investigation or audit, and (d) Maker shall indemnify and hold harmless
the holder with respect to all claims, damages, losses, liabilities, and
expenses (including reasonable attorney fees) asserted against or incurred by
the holder by reason of any failure to comply with, or any inaccuracy in, any
of the agreements, representations, and warranties contained in this
paragraph.

     Waivers.  No delay by the holder of this Note in the exercise of any
right or remedy shall operate as a waiver thereof.  No single or partial
exercise by the holder of any right or remedy shall preclude any other or
future exercise thereof or the exercise of any other fight or remedy.  No
waiver by the holder of any default or of any provision hereof shall be
effective unless in writing and signed by the holder.  No waiver of any right
or remedy on one occasion shall be a waiver of that right or remedy on any
future occasion.

     Maker waives demand for payment, presentment, notice of dishonor, and
protest of this Note and consents to any extension or postponement of time of
its payment, to any substitution, exchange, or release of all or any part of
any security given to secure this Note, to the addition of any party hereto,
and to the release, discharge, waiver, modification, or suspension of any
rights and remedies against any person who may be liable for the indebtedness
evidenced by this Note.

     Maker agrees that the interest rate on this Note is not usurious, and
Maker waives any defense or cause of action related to usury.

     Advances.  Payee will advance $2,000,000 to Maker upon execution of
this Note.  Maker from time to time may request additional advances (up to
$2,500,000 outstanding at anytime).  Any such additional advances shall be
made by Payee in his sole and unlimited discretion upon review of Maker's
financial condition and the value of collateral securing this Note.

     General.  In this Note, "maturity" means such time as the entire
remaining unpaid principal balance shall be or shall become due and payable
for any reason, including acceleration as provided above.
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     Applicable Law and Jurisdiction.  This Note shall be governed by and
interpreted according to the laws of the Commonwealth of Virginia, without
giving effect to principles of conflict of laws.  Maker irrevocably agrees
and consents that any action against Maker for collection or enforcement of
this Note may be brought in any state or federal court that has subject
matter jurisdiction and is located in, or whose district includes, Kent
County, Michigan, and that any such court shall have personal jurisdiction
over Maker for purposes of such action.

                              ETS INTERNATIONAL, INC.



                              By s/John D. McKenna
                                 ---------------------------------

                                 Its CEO
                                     -----------------------------

                              Address:  1401 Municipal Road, N.W.
                                        Roanoke, Virginia 24012
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