TENANT'S ESTOPPEL CERTIFICATE


TO: Beard Development Corporation
    1076 Thomas Jefferson
    N.W. Washington, D.C. 20007
    RE: James W. Miller

     The undersigned,  as Tenant of  approximately  6,694 square feet under that
certain-Lease  dated December 19, 1 996, made with James W. Miller ("Landlord")
as of even date herewith covering space in Landlord's office building located in
Charleston County, South Carolina, hereby certifies as follows:

     (1) That  the  undersigned  shall  enter  into  occupancy  of the  premises
described  in said  Lease by the  commencement  date of the  Lease as set  forth
therein;

     (2) That said Lease is in full force and effect and has not been  assigned,
modified, supplemented or amended in any way except: N/A

     (3) That said  Lease,  as  amended  as  indicated  in  paragraph  2 hereof,
represents the entire agreement between the parties as to said leasing;

     (4) That the commencement  date of the term of said Lease is as of the date
hereof;

     (5) That the  expiration  date of the term of said  Lease is  November  30,
2001.  The  undersigned  has no rights to renew or extend  the term of the Lease
except for an additional five (5) year extension as described in the Lease;

     (6) That all  conditions  of said Lease to be  performed  by Landlord as of
this date and necessary to the enforceability of said Lease have been satisfied;

     (7) That there are no defaults by either Tenant or Landlord thereunder, and
no event has occurred or situation exists which would, with the passage of time,
constitute a default under the Lease.  All  improvements  or work required under
the Lease to be made by the Landlord to date, if any, have been completed to the
satisfaction  of the  undersigned.  Charges for all labor and materials  used or
furnished  in  connection  with  improvements  and/or  alterations  made for the
account of the undersigned in the building have been paid in full.

     (8) That no rents have been  prepaid  more than __0__ months in advance and
full rental,  including  basic  minimum  rent,  if any, has not yet commenced to
accrue;

     (9) That on this date there are no existing  defenses,  offsets,  claims or
credits  which the  undersigned  has  against the  enforcement  of said Lease by
Landlord except for prepaid rent through (not to exceed two months);

     (10) The undersigned has paid to Landlord a security  deposit in the amount
of $16,569.00;

     (11) The undersigned does not have all governmental  permits,  licenses and
consents  required for the activities and  operations  being  conducted or to be
conducted by it in or around the building but shall acquire such approval by the
time the undersigned has begun occupying the premises; and

     (12)  That as of the  date  there  are no  actions,  whether  voluntary  or
otherwise,  pending against the  undersigned  under the bankruptcy or insolvency
laws of the United States or any state thereof.

     The undersigned  acknowledges that Beard Development  Corporation will rely
on this  certificate in connection  with the making of a loan to Landlord,  that
the truthfulness  and accuracy of the foregoing are conditions  precedent to the
funding of said loan and that assignment of Landlord's  interest in the Lease is
required as additional collateral for the Loan.

EXECUTED this day of December, 1996.
Witnesses:
ENVIROMETRICS, INC. (SEAL)
By:

Name:
Title: