NGS MECHANICAL, INC.

                          CERTIFICATE OF INCORPORATION

      The undersigned incorporator hereby forms a corporation under the Business
Corporation Act of the State of Connecticut:

      Article I. The name of the corporation is: NGS Mechanical, Inc.

      Article II. There shall be one class of capital stock, designated "Common
Stock" no par value, of which there shall be a total of 20,000 authorized
shares.

      Article III. The name and business address of initial registered agent is
as follows:

            O. Kay Comendul
            107 Selden Street
            Berlin, CT 06037

      The residence address of the initial registered agent is as follows:

            343 Long Hill Road
            Wallingford, CT 06492

      The initial registered agent hereby accepts appointment:


                                                        /s/ O. Kay Comendul

      Article IV. NGS Mechanical, Inc. ("Company") shall indemnify and advance
reasonable expenses to an individual made or threatened to be made a party to a
proceeding because he/she is or was a Director of the Company to the fullest
extent permitted by law under Section 33-771 and Section 33-773 of the
Connecticut General Statutes, as may be amended from time to time ("Connecticut
General Statutes"). The Company shall also indemnify and advance reasonable
expenses under Connecticut General Statutes Sections 33-770 to 33-778,
inclusive, as amended, to any officer, employee or agent of the Company who is
not a Director to the same extent as a Director and to such further extent,
consistent with public policy, as may be provided by contract,


the Certificate of Incorporation of the Company, the Bylaws of the Company or a
resolution of the Board of Directors. In connection with any advance for such
expenses, the Company may, but need not, require any such officer, employee or
agent to deliver a written affirmation of his/her good faith belief that he/she
has met the relevant standard of conduct or a written undertaking to repay any
funds advanced for expenses if it is ultimately determined that he/she is not
entitled to indemnification. The Board of Directors, by resolution, the general
counsel of the Company, or such additional officer or officers as the Board of
Directors may specify, shall have the authority to determine that
indemnification or advance for such expenses to any such officer, employee or
agent is permissible and to authorize payment of such indemnification or advance
for expenses. The Board of Directors, by resolution, the general counsel of the
Company, or such additional officer or officers as the Board of Directors may
specify, shall also have the authority to determine the terms on which the
Company shall advance expenses to any such officer, employee or agent, which
terms need not require delivery by such officer, employee or agent of a written
affirmation of his/her good faith belief that he/she has met the relevant
standard of conduct or a written undertaking to repay any funds advanced for
such expenses if it is ultimately determined that he/she is not entitled to
indemnification.

      The indemnification and advance for expenses provided for herein shall not
be deemed exclusive of any other rights to which those indemnified or eligible
for advance for expenses may be entitled under Connecticut law as in effect on
the effective date hereof and as thereafter amended or any Bylaw, agreement,
vote of shareholders or disinterested directors or otherwise, both as to action
in such person's official capacity and as to action in another capacity while
holding such office, and shall continue as to a person who has ceased to be a
director, officer, employee or agent and shall inure to the benefit of the
heirs, executors and administrators of such a person.

      No lawful repeal or modification of this article or the adoption of any
provision inconsistent herewith by the Board of Directors and shareholders of
the Company or change in statute shall apply to or have any effect on the
obligations of the Company to indemnify or to pay for or reimburse in advance
expenses incurred by a director, officer, employee or agent of the Company in
defending any proceeding arising out of or with respect to any acts or omissions
occurring at or prior to the effective date of such repeal, modification or
adoption of a provision or statute change inconsistent herewith.

      Dated this 24th day of January, 2001.


/s/ O. Kay Comendul, Incorporator
107 Selden Street
Berlin, CT 06037