Exhibit 2.1

                                                                         










                            SHARE PURCHASE AGREEMENT

                                     BETWEEN

                            THERMOSPECTRA CORPORATION

                                       AND

                         THERMO INSTRUMENT SYSTEMS INC.


                          _____________________________

                            Dated as of July 30, 1997
                          _____________________________

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                            SHARE PURCHASE AGREEMENT

             THIS SHARE PURCHASE AGREEMENT (this "Agreement") dated as of
        July 30, 1997 is between ThermoSpectra Corporation ("THS"), a
        Delaware corporation, and Thermo Instrument Systems Inc. ("THI"),
        a Delaware corporation.

                              Preliminary Statement

             1.   Life Sciences International Limited ("LSI"), which is a
        majority-owned subsidiary of THI, owns, directly or through
        wholly-owned subsidiaries, all of the issued and outstanding
        shares (the "Shares") of NESLAB Instruments, Inc. ("NESLAB"), a
        New Hampshire corporation, NESLAB Instruments Europa BV, a
        Netherlands corporation ("NESLAB BV"), and NESLAB Instruments
        Ltd., a United Kingdom private Company ("NESLAB Ltd.").  THI, LSI
        and those of LSI's wholly-owned subsidiaries that own Shares are
        referred to individually as a "Seller" and collectively as the
        "Sellers".  NESLAB, NESLAB BV and NESLAB Ltd. are referred to
        herein as the "Company".

             2.   THS desires to purchase, or cause its wholly-owned
        subsidiaries to purchase, and THI desires to sell, or to cause
        its subsidiaries to sell, the Shares for the consideration set
        forth below, subject to the terms and conditions of this
        Agreement.

             NOW THEREFORE, in consideration of the mutual promises
        hereinafter set forth and other good and valuable consideration,
        the receipt of which is hereby acknowledged, the parties hereby
        agree as follows:

        SECTION 1 - PURCHASE AND SALE OF THE SHARES

             1.1  Purchase of the Shares from the Sellers.  Subject to
        and upon the terms and conditions of this Agreement, at the
        closing of the transactions contemplated by this Agreement (the
        "Closing"), THI shall cause its subsidiaries to sell, transfer,
        convey, assign and deliver to THS, or its wholly-owned
        subsidiaries, and THS or its wholly-owned subsidiaries shall
        purchase, acquire and accept the Shares.  At the option of THS,
        THS may acquire the Shares through the merger of a subsidiary of
        THS with and into NESLAB, pursuant to which merger the Sellers'
        shares of NESLAB would be canceled in exchange for the
        consideration set forth in Section 3.1 below.

             1.2  Further Assurances.   At any time and from time to time
        after the Closing, at THS's request and without further
        consideration, each Seller shall promptly execute and deliver
        such instruments of sale, transfer, conveyance, assignment and
        confirmation, and take all such other action as THS may
        reasonably request, more effectively to transfer, convey and
        assign to THS, and to confirm THS's title to, all of the Shares
        owned by such Seller, to put THS in actual possession and
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        operating control of the assets, properties and business of the
        Company, to assist in exercising all rights with respect thereto
        and to carry out the purpose and intent of this Agreement.

             1.3  Purchase Price for the Shares.  

                  (a)  The purchase price to be paid by THS for the
        Shares (the "Purchase Price") shall consist of 2,869,717 shares
        of common stock, $.01 par value, of THS (the "THS Shares"). 

                  (b)  THS and THI acknowledge and agree that the
        Purchase Price represents an estimate of the sum of (i) the net
        operating assets of the Company as of June 28, 1997, plus (ii) a
        percentage of the total goodwill associated with THI's
        acquisition of LSI equal to the sales of the Company for the 1996
        fiscal year relative to the total sales of LSI during such period
        (the "Goodwill Percentage").  Promptly following the Closing
        Date, but in any event no later than September 30, 1997, THI will
        prepare a draft statement of the net operating assets of the
        Company (the "Company Net Asset Statement") as of June 28, 1997,
        and a draft calculation of THI's total goodwill associated with
        the acquisition of LSI (the "THI Goodwill Statement") as of March
        12, 1997, the date of THI's acquisition of LSI.  THS will review
        such statements and provide THI with any objections thereto
        within 30 days after THS's receipt thereof.  If THS does not
        object within such 30-day period, then the THI Goodwill Statement
        and the Company Net Asset Statement shall be deemed to be
        accepted by THS and shall become final.  If THS does object to
        either statement, then the parties will use best efforts to
        resolve any such objections within 30 days.  If the parties are
        unable to resolve such objections within such 30-day period, then
        any disputed items will be resolved by an accounting firm
        designated jointly by THS and THI and the statements shall be
        finalized in accordance with the determination of such firm.
        Upon finalization of the Companies Net Asset Statement and the
        THI Goodwill Statement as provided above, the Purchase Price
        shall be increased or decreased, as the case may be, by (A) the
        amount by which the net operating assets of the Companies as
        shown on the Companies Net Asset Statement are greater than or
        less than $18,645,671 and (B) the amount by which the Goodwill
        Percentage of THI's total goodwill as shown on the THI Goodwill
        Statement is greater than or less than $58,740,441.  Any payment
        due by THS or THI to the other under this section 1.3(b) shall be
        accompanied by interest from the date hereof at a rate equal to
        the Commercial Paper Composite Rate plus 25 basis points.  For
        purposes of this section 1.3(b), "goodwill" means cost in excess
        of net tangible assets acquired, and does not include any
        restructuring or similar costs or reserves accrued in connection
        with actions taken by the businesses of LSI after March 12, 1997
        to reduce costs or enhance profitability, and "net operating
        assets" means tangible assets, minus total liabilities, 
        determined in accordance with THI's accounting policies.

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             1.4  Closing.  The Closing shall take place at the offices
        of THI at 81 Wyman Street, Waltham, Massachusetts.  At the
        Closing THI shall deliver, or cause its subsidiaries to deliver,
        certificates evidencing the Shares duly endorsed in blank or with
        stock powers duly executed.  At the Closing THS shall deliver one
        or more certificates representing the THS Shares registered in
        the name of THI and/or such of its subsidiaries as THI shall
        designate.

        SECTION 2 - REPRESENTATIONS AND WARRANTIES OF THI

             Except as set forth on the disclosure schedule delivered to
        THS on the date hereof (the "Disclosure Schedule"), THI
        represents and warrants to THS as follows.  The term "knowledge,"
        when used in this Agreement, shall mean actual knowledge after
        reasonable investigation.

             2.1  Organization and Qualification.  Each of the Sellers
        and the Company is a corporation duly organized, validly existing
        and in good standing under the laws of its jurisdiction of
        incorporation and has full corporate power and authority to own,
        lease and operate its assets and to carry on its business as now
        being and as heretofore conducted.  Each of  the Sellers and the
        Company is qualified or otherwise authorized to transact business
        as a foreign corporation in all jurisdictions in which such
        qualification or authorization is required by law, except for
        jurisdictions in which the failure to be so qualified or
        authorized would not have a material adverse effect on the
        assets, properties, business, results of operations, condition
        (financial or otherwise) or prospects of the Company taken as a
        whole.

             2.2  Authority. THI has full right, power, capacity and
        authority to execute, deliver and perform this Agreement and to
        consummate the transactions contemplated hereby and each of the
        Sellers has full right, power, capacity and authority to
        consummate the transactions contemplated hereby to be performed
        by such Seller. The execution, delivery and performance of this
        Agreement and the consummation of the transactions contemplated
        hereby have been duly and validly authorized by all necessary
        corporate action on the part of THI. This Agreement has been duly
        and validly executed and delivered by THI and constitutes the
        valid and binding obligation of THI, enforceable against it in
        accordance with the terms hereof.  Neither the execution,
        delivery and performance of this Agreement, nor the consummation
        of the transactions contemplated hereby will (i) conflict with or
        result in a violation, breach, termination or acceleration of, or
        default under (or would result in a violation, breach,
        termination, acceleration or default with the giving of notice or
        passage of time, or both) any of the terms, conditions or
        provisions of the organizational documents of any Seller or
        Company, or of any note, bond, mortgage, indenture, license,
        agreement or other instrument or obligation to which any of
        Seller or Company is a party or by which any Seller or Company or
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        any of their respective properties or assets may be bound or
        affected; (ii) result in the violation of any order, writ,
        injunction, decree, statute, rule or regulation applicable to any
        Seller or the Company or any of their respective properties or
        assets; (iii) result in the imposition of any lien, encumbrance,
        charge or claim upon any assets of any of the Company; or (iv)
        entitle any employee of the Company to severance or other
        payments or create any other obligation to an employee.  No
        consent or approval by, or notification to or filing with, any
        court, governmental authority or third party is required in
        connection with the execution, delivery and performance of this
        Agreement by any Seller or the consummation of the transactions
        contemplated hereby.

             2.3  Capitalization and Title to Shares.

                  (a)  The authorized share capital of the Company is set
        forth on Exhibit A hereto.  The Seller set forth opposite the
        name of the Company on Exhibit A is the record and beneficial
        owner of all of the issued and outstanding shares of the Company.
        All of the Shares are duly authorized and are validly issued,
        fully paid, nonassessable and free of preemptive rights. 

                  (b)  There are no other shares of capital stock of any
        Company authorized or outstanding or any subscriptions, options,
        conversion or exchange rights, warrants, repurchase or redemption
        agreements, or other agreements or commitments obligating any
        Company to issue, transfer, sell, repurchase or redeem any shares
        of its capital stock or other securities of any Company.  There
        are no written shareholder agreements, voting trusts, proxies or
        other agreements, instruments or understandings with respect to
        the voting of the capital stock of any Company.  The books and
        records of each Company, including without limitation the books
        of account, minute books, stock certificate books and stock
        ledgers, are complete and correct and accurately reflect the
        conduct of the business and affairs of such Company.

             2.4  Subsidiaries and Other Affiliates. 

                  (a)  The Disclosure Schedule sets forth all
        Subsidiaries of the Company and the jurisdiction in which each is
        incorporated.  All shares of the capital stock of each Subsidiary
        owned by the Company are owned free and clear of any charges,
        liens, encumbrances, security interests or adverse claims.  As
        used in this Agreement, "Subsidiary" means any corporation or
        other legal entity of which a party to this Agreement owns,
        directly or indirectly, fifty percent (50%) or more of the stock
        or other equity interest entitled to vote for the election of
        directors and representations, warranties and covenants referring
        to the Company contained herein shall be deemed to mean the
        Company and each of its Subsidiaries, both separately and
        together as a consolidated whole, unless and except to the extent
        expressly indicated otherwise.

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                  (b)  There are no other shares of capital stock of any
        Subsidiary of the Company authorized or outstanding or any
        subscriptions, options, conversion or exchange rights, warrants,
        repurchase or redemption agreements, or other agreements or
        commitments obligating any Subsidiary of the Company to issue,
        transfer, sell, repurchase or redeem any shares of its capital
        stock or other securities.  There are no shareholder agreements,
        voting trusts, proxies or other agreements, instruments or
        understandings with respect to the voting of the capital stock of
        any Subsidiary of the Company.

                  (c)  Except for its Subsidiaries, the Company does not,
        directly or indirectly, own any material equity interest in any
        corporation, partnership, joint venture or other entity.

             2.5  Financial Statements.  THI has delivered to THS prior
        to the execution of this Agreement true and complete copies of:
        the unaudited consolidated balance sheet of the Company as at
        June 28, 1997  (the "Balance Sheet"), and the unaudited
        consolidated statements of earnings of the Company for the three
        years ended December 31, 1996 and for the six-month period ended
        June 28, 1997  (collectively, the "Financial Statements").  The
        Financial Statements have been prepared from, and are in
        accordance with, the books and records of LSI and fairly present
        the financial condition, results of operations, and cash flows of
        the Company as at the dates and for the periods indicated, in
        each case in accordance with generally accepted accounting
        principles applied on a basis consistent with previous years
        subject to normal year-end adjustments and footnote disclosures,
        which in the aggregate are not material.

             2.6  Absence of Undisclosed Liabilities; No Dealings with
        Affiliates.  As of the date of the Balance Sheet, the Company had
        no material liabilities or obligations of any nature, whether
        accrued, absolute, contingent or otherwise and whether due or to
        become due (including without limitation, liabilities as
        guarantor or otherwise with respect to obligations of others or
        liabilities for taxes due or then accrued or to become due),
        required to be reflected or disclosed on the Balance Sheet that
        were not adequately reflected or reserved against on the Balance
        Sheet.  The Company has no liabilities of the type required to be
        reflected or disclosed on a balance sheet in accordance with
        generally accepted accounting principles, other than liabilities
        (i) adequately reflected or reserved against on the Balance
        Sheet, (ii) incurred since the date of the Balance Sheet in the
        ordinary course of business and consistent with past practice,
        (iii) that would not, in the aggregate, have a material adverse
        effect on the Company taken as a whole, or (iv) disclosed in this
        Agreement.  The Company has no contractual arrangement with or
        commitment to or from any of its stockholders, officers,
        management, directors or employees (or their family members)
        other than such as may have been entered into in the normal
        course of employment, including, without limiting the generality
        of the foregoing, being directly or indirectly a joint investor
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        or coventurer with respect to, or owner, lessor, lessee, licenser
        or licensee of, any real or personal property, tangible or
        intangible, owned or used by, or a lender to or debtor of, the
        Company.

             2.7  Taxes.  The Company has accurately prepared and duly
        and timely filed all federal, state, local, provincial or foreign
        tax and other returns and reports which were required to be
        filed, in respect of all income, franchise, excise, sales, use,
        property (real and personal), VAT, payroll and other taxes,
        levies, imports, duties, license and registration fees, charges
        or withholdings of any nature whatsoever (collectively "Taxes"),
        and to the extent the liabilities of the Company for Taxes have
        not been fully discharged, adequate reserves have been
        established on the Balance Sheet.  None of the federal, state,
        local, provincial or foreign Tax returns of the Company has been
        audited or examined by the governmental authority having
        jurisdiction.  No waivers of any statutes of limitation are in
        effect in respect of any Taxes.  The Company is not in default in
        the payment of any Taxes due and payable or on any assessments
        received in respect thereof, and there are no claims pending or,
        to the best knowledge of the Company and the Sellers, threatened,
        against the Company for past due Taxes. All Taxes incurred but
        not yet due have been fully accrued on the books of the Company
        or full reserves have been established therefor; the reserves
        indicated on the Balance Sheet are also adequate to cover all
        Taxes that may become payable by the Company in future periods in
        respect of any transactions or sales occurring on or prior to the
        date of the Balance Sheet.  Without limiting the generality of
        the foregoing, the Company has withheld or collected from each
        payment made to each of their employees, consultants or non-U.S.
        payees, the amount of all Taxes required to be withheld or
        collected therefrom, and has paid the same to the proper tax
        receiving officers or authorized depositories.

             2.8  Properties.  The Company owns and has good title to all
        of the assets and properties reflected as owned by it on the
        Balance Sheet or acquired by the Company since the date of the
        Balance Sheet (except personal property sold or otherwise
        disposed of in the ordinary course of business since the date of
        the Balance Sheet), free and clear of any lien, claim or other
        encumbrance, except for (i) the liens, claims or other
        encumbrances reflected on the Balance Sheet, (ii) assets and
        properties disposed of, or subject to purchase or sales orders,
        in the ordinary course of business since the date of the Balance
        Sheet, (iii) liens, claims or other encumbrances securing the
        liens of materialmen, carriers, landlords and like persons, all
        of which are not yet due and payable, (iv) liens for taxes not
        yet delinquent and (v) liens, claims, other encumbrances or
        defects in title that, in the aggregate, are not material to the
        Company taken as a whole.  The Company owns or has a valid
        leasehold interest in all of the buildings, structures, leasehold
        improvements, equipment and other tangible property material to
        the Company taken as a whole, all of which are in good and
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        sufficient operating condition and repair, ordinary wear and tear
        excepted and the Company has not received any notice that any
        such property is in violation in any material respect of any
        existing law or any building, zoning, health, safety or other
        ordinance, code or regulation.

             2.9  Hazardous Materials. 

                  (a)  There has been no generation, use, handling,
        storage or disposal of any Hazardous Materials in violation of
        common law or any applicable environmental law at any site owned
        or premises leased by the Company during the period of the
        Company's ownership or lease that could have a material adverse
        effect on the Company taken as a whole.  Nor has there been or is
        there threatened any release of any Hazardous Materials on or at
        any such site or premises during such period in violation of
        common law or any applicable environmental law or which created
        or will create an obligation to report or remediate such release,
        which release or failure to report or remediate could have a
        material adverse effect on the Company taken as a whole.  For
        purposes of this Agreement, "Hazardous Material" means any
        medical waste, flammable, explosive or radioactive material, or
        any hazardous or toxic waste, substance or material, including
        substances defined as "hazardous substances," "hazardous
        materials," "solid waste" or "toxic substances" under any
        applicable laws or ordinances relating to hazardous or toxic
        materials and substances, air pollution (including noise and
        odors), water pollution, liquid and solid waste, pesticides,
        drinking water, community and employee health, environmental land
        use management, stormwater, sediment control, nuisances,
        radiation, wetlands, endangered species, environmental
        permitting, petroleum products, and all rules and regulations
        promulgated pursuant to any such laws and ordinances.

                  (b)  THI has previously made available to THS copies of
        all documents concerning any environmental or health and safety
        matter that could have a material adverse effect on the Company
        taken as a whole, if any, and copies of any environmental audits
        or risk assessments, site assessments, documentation regarding
        off-site disposal of Hazardous Materials, spill control plans and
        material correspondence with any governmental authority regarding
        the foregoing.

             2.10 Accounts Receivable.  All accounts and notes receivable
        of the Company shown on the Balance Sheet and all accounts and
        notes receivable acquired by the Company subsequent to the date
        of the Balance Sheet have arisen in the ordinary course of
        business and have been collected, or are in the process of
        collection and are collectible in the ordinary course of business
        and in any event within nine months from the Closing Date, in the
        aggregate recorded amounts thereof, less the applicable
        allowances reflected on the Balance Sheet with respect to the
        accounts and notes receivable shown thereon, or set up consistent
        with past practice on the books of the Company with respect to
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        the accounts and notes receivable acquired subsequent to the date
        of the Balance Sheet.

             2.11 Inventories.  All Inventories (as defined below) of the
        Company are of a quality and quantity usable and saleable in the
        ordinary course of business, except for obsolete items and items
        of below- standard quality, all of which are in the aggregate
        immaterial to the Company taken as a whole.  Items included in
        such Inventories are carried on the books of the Company, and are
        valued on the Balance Sheet, at the lower of cost or market.  The
        value of obsolete materials and materials of below-standard
        quality or quantity has been written down on the books of account
        of the Company to realizable market value.  The term
        "Inventories" includes all stock of raw materials,
        work-in-process and finished goods, including but not limited to
        finished goods purchased for resale, held by the Company for
        manufacturing, assembly, processing, finishing, sale or resale to
        others, from time to time in the ordinary course of business of
        the Company in the form in which such inventories then are held
        or after manufacturing, assembling, finishing, processing,
        incorporating with other goods or items, refining or the like.

             2.12 Purchase and Sale Commitments.  No outstanding purchase
        commitments by the Company are in excess of the normal, ordinary
        and usual requirements of the Company, and the aggregate of the
        contract prices to which the Company has agreed in any
        outstanding purchase commitments is not so excessive when
        compared with current market prices for the relevant commodities
        or services that a material loss is likely to result.  No
        outstanding sales commitment by the Company obligates the Company
        to sell any product or service at a price which, because of
        currently prevailing and projected costs of materials or labor,
        is likely to result, when all such sales commitments are taken in
        the aggregate, in a material loss to the Company taken as a
        whole. There are no material suppliers to the Company of
        significant goods or services with respect to which practical
        alternative sources of supply, or comparable products, are not
        available on comparable terms and conditions.

             2.13 Governmental Authorizations.  The Company has all
        governmental permits, licenses, franchises, concessions, zoning
        variances and other approvals, authorizations and orders
        (collectively "Permits") material to the Company taken as a
        whole.  All such Permits are presently in full force and effect,
        the Company is in compliance with the requirements thereof, no
        suspension or cancellation of any of them is threatened so far as
        is known to the Sellers or the Company, and the sale of the
        Shares as contemplated hereby will not adversely affect the
        validity or effectiveness of, and will not require, for retention
        thereof after such sale, the consent or approval of any party to,
        or any other person or governmental authority having jurisdiction
        of, any such Permit.  None of the Company or the Sellers has any
        knowledge of any fact or circumstance which would prevent, limit
        or restrict it from continuing to operate its business in the
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        present manner, and no new requirements pertaining to the manner
        of operating its business have been issued or announced by any
        governmental authority during the past year nor are there any
        disputes pending between the Company and any governmental
        authority relating to the Company's operations as presently being
        conducted or actively considered.

             2.14 Intellectual Property.  The Company owns, or is
        licensed to use, or otherwise has the right to use all patents,
        trademarks, service marks, trade names, trade secrets,
        franchises, and copyrights, and all applications for any of the
        foregoing, and all technology, know-how and processes necessary
        for the conduct of its businesses as now conducted (collectively,
        the "Proprietary Rights").  A list of all such copyrights,
        trademarks, tradenames and patents, and all applications
        therefor, has been furnished or made available to THS. None of
        the Company or the Sellers is aware of any claim by any third
        party that the business of the Company as currently conducted or
        proposed to be conducted infringes upon the unlicensed
        Proprietary Rights of others, nor has the Company or any of the
        Sellers received any notice or claim from any third party of such
        infringement by the Company.  None of the Company or the Sellers
        is aware of any infringement by any third party on, or any
        competing claim of right to use or own any of, the Proprietary
        Rights of the Company.  The Company has the right to use, free
        and clear of claims or rights of others, all customer lists and
        computer software material to its business as presently
        conducted.  To the best knowledge of the Company and the Sellers,
        none of the activities of the employees of the Company on behalf
        of the Company violates any agreements or arrangements which any
        such employees have with former employers in a way which is
        materially adverse to the business of the Company taken as a
        whole.

             2.15 Insurance.  The Company is not in default with respect
        to any provisions of any policy of general liability, fire, title
        or other form of insurance held by it, the Company is current in
        the payment of all premiums due on such insurance and the Company
        has not failed to give any notice or present any claim thereunder
        in due and timely fashion, except for claims that are immaterial
        in both the nature of the claim and in the amount of such claim.
        The Company maintains insurance on all of their assets and
        business (including products liability insurance) from insurers
        which are financially sound and reputable, in amounts and
        coverages and against the kinds of risks and losses reasonably
        prudent to be insured against by corporations engaged in the same
        or similar businesses.  No basis exists which would jeopardize
        the coverage under any such insurance.  No such insurance will be
        terminated or canceled by reason of the execution, delivery and
        performance of this Agreement or the consummation of the
        transactions contemplated hereby.  THI has previously furnished
        or made available to THS all policies of general liability, fire,
        title or other forms of insurance applicable to the Company and a

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        description of all claims pending thereunder other than health or
        dental insurance claims.

             2.16 Employee Benefit Plans. 

                  (a)  THI has made available or furnished to THS true
        and complete copies of each pension, profit-sharing, deferred
        compensation, incentive compensation, severance pay, retirement,
        welfare benefit or other plan or arrangement providing benefits
        to employees or retirees, including both those that do and do not
        constitute employee benefit plans within the meaning of Section
        3(3) of the Employee Retirement Income Security Act of 1974, as
        amended (the "ERISA"), currently maintained or contributed to by
        THI or any of its affiliates for the benefit of the employees or
        retirees of the Company (each, a "Plan").

                  (b)  Except as set forth on the Disclosure Schedule,
        (i) each such Plan that is an "employee pension benefit plan"
        within the meaning of Section 3(2) of ERISA is being operated and
        administered in compliance with Section 401(a) of the Code, a
        favorable determination letter has been obtained from the
        Internal Revenue Service (the "IRS") for such Plan, and there is
        no accumulated funding deficiency, as defined in Section
        302(a)(2) of ERISA or Section 412 of the Code, with respect to
        such Plan; (ii) there has been no non-exempt "prohibited
        transaction" within the meaning of Section 406 of ERISA or
        Section 4975 of the Code involving the assets of any Plan nor any
        "reportable event" within the meaning of Section 4043 of ERISA
        with respect to any Plan; (iii) all required employer
        contributions to such Plan have been made (or, in the case of
        contributions not yet due, have been accrued on the Balance
        Sheet); (iv) THI has made available to THS as to each such Plan a
        true and correct copy of (w) the annual report (Form 5500) filed
        with the IRS for each of the three most recent plan years, (x)
        each plan, trust agreement, group annuity contract and insurance
        contract, if any, relating to such Plan, (y) each actuarial
        report prepared for each of the last three years for each Plan
        and (z) each summary plan description distributed to participants
        in each Plan and each summary of material modifications to each
        Plan (as defined in ERISA); and (v) each such Plan is, and at all
        relevant times has been, in compliance with ERISA, the Code and
        the terms of such Plan.  None of the Sellers or the Company or
        their respective affiliates has ever participated in a
        "multiemployer pension plan" as defined in Section 3(37) of
        ERISA.

                  (c)  Except as set forth on the Disclosure Schedule,
        the Company has no obligation to provide any welfare benefits to
        retired or former employees other than continuation of welfare
        benefits as required by applicable law.

                  (d)  The Company has no liability under or with respect
        to any employee benefit plans or arrangements that it no longer
        maintains or in which it no longer participates.
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             2.17 Agreements and Documents.  THI has previously furnished
        or made available to THS true, correct and complete copies of
        each document that is referred to or otherwise related to any of
        the following items referred to in this Section 2.17:

                  (a)  each document related to interests in real
        property owned, leased or otherwise used or claimed by the
        Company;

                  (b)  (i) each agreement of the Company made in the
        ordinary course of business which involves aggregate future
        payments by or to the Company of more than one hundred fifty
        thousand dollars ($150,000) or any agreement made in the ordinary
        course of business whose term extends beyond one year after the
        date hereof; (ii) each agreement containing any covenant
        restricting the freedom of the Company to compete in any line of
        business or with any person; and (iii) each agreement of the
        Company not made in the ordinary course of business which is or
        was to be performed after July 30, 1997;

                  (c)  all employment or similar compensation agreements
        of the Company which may not be terminated by the Company without
        penalty within thirty days after the Closing;

                  (d)  all bonus, incentive compensation, deferred
        compensation, profit-sharing, stock option, retirement, pension,
        severance, indemnification, insurance, death benefit or other
        fringe benefit plans, agreements or arrangements of any of the
        Company (or applying to the Company) in effect, or under which
        any amounts remain unpaid, on the date hereof or to become
        effective after the date hereof;

                  (e)  all labor unions or other organizations
        representing, purporting to represent or attempting to represent
        any employees of the Company, and all collective bargaining
        agreements of the Company with any labor unions or other
        representatives or employees;

                  (f)  each agreement or other instrument or arrangement
        defining the terms on which any indebtedness of the Company (or a
        guarantee by the Company of indebtedness) is or may be issued;
        and

                  (g)  the names and addresses of all banks in which the
        Company has accounts or lines of credit, and with respect to each
        such account or line of credit, the names of all persons
        authorized to draw thereon.

                  The Company is not a party to any oral contract or
        agreement which would be required to have been furnished or made
        available to THS under this Section 2.17 had such contract or
        agreement been committed to writing.

                                       11PAGE
<PAGE>
             2.18 Validity.  There is no default or claimed or purported
        or alleged default, or basis on which with notice or lapse of
        time or both (including notice of this Agreement), a default
        would exist, in any obligation on the part of any party
        (including the Company) to be performed under any lease,
        contract, plan, policy or other instrument or arrangement
        referred to in Section 2.17 or otherwise in this Agreement.

             2.19 No Changes.  Since the date of the Balance Sheet there
        has not been:

                  (a)  any material adverse change in the business of the
        Company taken as a whole;

                  (b)  any material damage, destruction or loss (whether
        or not covered by insurance) adversely affecting the business of
        the Company taken as a whole;

                  (c)  any declaration, setting aside or payment of any
        dividend, or other distribution, in respect of any capital stock
        of the Company or any direct or indirect redemption, purchase or
        other acquisition of such stock;

                  (d)  any option to purchase any capital stock of the
        Company granted to any person, or any employment or deferred
        compensation agreement entered into between the Company and any
        of its stockholders, officers, directors, employees or
        consultants;

                  (e)  any issuance or sale by the Company of any stock,
        bonds or other corporate securities, or any partial or complete
        formation, acquisition, disposition or liquidation of the
        Company;

                  (f)  any labor union activity (including without
        limitation any negotiation, or request for negotiation, with
        respect to any union representation or any labor contract)
        respecting the Company;

                  (g)  any statute, rule or regulation, or, to the best
        knowledge of the Company and the Sellers, any government policy,
        adopted which may materially and adversely affect the business of
        the Company;

                  (h)  any mortgage, lien, attachment, pledge,
        encumbrance or security interest created on any asset, tangible
        or intangible, of the Company, or assumed, either by the Company
        or by others, with respect to any such assets, except for liens
        permitted under Section 2.8;

                  (i)  any indebtedness or other liability or obligation
        (whether absolute, accrued, contingent or otherwise) incurred, or
        other transaction (except that is reflected in this Agreement)
        engaged in, by the Company, except those in the ordinary course
                                       12PAGE
<PAGE>
        of business that are individually, or in the aggregate to one
        group of related parties, less than fifty thousand dollars
        ($50,000);

                  (j)  any obligation or liability discharged or
        satisfied by the Company, except items included in current
        liabilities shown on the Balance Sheet and current liabilities
        incurred since the date of the Balance Sheet in the ordinary
        course of business which are individually, or in the aggregate to
        one group of related parties, less than twenty five thousand
        dollars ($25,000) in amount;

                  (k)  any sale, assignment, lease, transfer or other
        disposition of any tangible asset of the Company, except in the
        ordinary course of business, or any sale, assignment, lease,
        transfer or other disposition of its patents, trademarks, trade
        names, brand names, copyrights, licenses or other intangible
        assets;

                  (l)  any amendment, termination or waiver of any
        material right belonging to the Company;

                  (m)  any increase in the compensation or benefits
        payable or to become payable by the Company to any of its
        officers or employees;

                  (n)  any other action or omission by the Company, or
        the passage of any resolution, other than in the ordinary course
        of business.

             2.20 Litigation or Proceedings.  The Company is not engaged
        in, or a party to, or, to the best of the Sellers' and the
        Company's knowledge, threatened with, any claim or legal action
        or other proceeding before any court, any arbitrator of any kind
        or any governmental authority, nor does any basis for any claim
        or legal action or other proceeding or governmental investigation
        exist.  There are no orders, rulings, decrees, judgments or
        stipulations to which the Company is a party by or with any
        court, arbitrator or governmental authority affecting the
        Company.

             2.21 Compliance with Laws.  The Company (i) has not been and
        is not in violation of any applicable building, zoning,
        occupational safety and health, pension, export control,
        environmental or other federal, state, local or foreign law,
        ordinance, regulation, rule, order or governmental policy
        applicable to it; (ii) has not received any complaint from any
        governmental authority, and to the best knowledge of the Sellers
        and the Company, none is threatened, alleging that the Company
        has violated any such law, ordinance, regulation, rule, order or
        governmental policy; (iii) has not received any notice from any
        governmental authority of any pending proceedings to take all or
        any part of the properties of the Company (whether leased or
        owned) by condemnation or right of eminent domain and, to the
                                       13PAGE
<PAGE>
        best knowledge of the Sellers and the Company, no such proceeding
        is threatened; and (iv) is not a party to any agreement or
        instrument, or subject to any charter or other corporate
        restriction or judgment, order, writ, injunction, rule,
        regulation, code or ordinance, which materially and adversely
        affects, or might reasonably be expected materially and adversely
        to affect the business of the Company.

             2.22 Labor Matters.  There are no labor organizing
        activities, election petitions or proceedings, labor strikes,
        disputes, slowdowns, work stoppages or unfair labor practice
        complaints pending or, to the best knowledge of the Sellers and
        the Company, threatened against the Company or between the
        Company and any of its employees.

             2.23 Recalls.  There is no basis for the recall, withdrawal
        or suspension of any approval by any governmental authority with
        respect to any product sold or proposed to be sold by the
        Company.  None of the products of any of the Company is subject
        to any recall proceedings and to the best of its knowledge no
        such proceedings have been threatened. 

             2.24 Brokers and Finders.  None of the Sellers or the
        Company has employed any broker, agent or finder or incurred any
        liability on behalf of any of the Sellers or the Company or for
        any brokerage fees, agents' commissions or finders' fees in
        connection with the transactions contemplated hereby.

             2.25 Powers of Attorney.  The Company has no powers of
        attorney or similar authorizations outstanding.

             2.26 No Termination of Relationship.  As of the date hereof,
        none of the Sellers or the Company has any reason to expect that
        any relationship between the Company and a material distributor,
        customer, supplier, lender, employee or other person will be
        terminated or adversely affected as a result of the transactions
        contemplated by this Agreement.

             2.27 All Information.  THS has been furnished in writing
        prior to the execution of this Agreement all information as to
        the business of the Company material to a reasonable buyer's
        determination to enter into this Agreement and to consummate the
        transactions contemplated hereby.

             2.28 Statements True and Correct.  The statements contained
        herein or in any written documents prepared and delivered by or
        on behalf of THI pursuant to the terms hereof are true, complete
        and correct in all material respects, and such documents do not
        omit any material fact required to be stated herein or therein or
        necessary to make the statements contained herein or therein not
        misleading.

                                      14PAGE
<PAGE>
        SECTION 3 - REPRESENTATIONS AND WARRANTIES OF THS
             THS represents and warrants to THI as follows.

             3.1  Organization.   THS is a corporation duly organized,
        validly existing and in good standing under the laws of the state
        of Delaware and has full corporate power and authority to own,
        lease and operate its assets and to carry on its business as now
        being and as heretofore conducted. 

             3.2  Authority. THS has full right, power, capacity and
        authority to execute, deliver and perform this Agreement and to
        consummate the transactions contemplated hereby. The execution,
        delivery and performance of this Agreement and the consummation
        of the transactions contemplated hereby have been duly and
        validly authorized by all necessary corporate action on the part
        of THS, except that approval of the THS shareholders is required
        to list the THS Shares on the AMEX.  This Agreement has been duly
        and validly executed and delivered by THS and constitutes the
        valid and binding obligation of THS, enforceable against it in
        accordance with the terms hereof.  Neither the execution,
        delivery and performance of this Agreement nor the consummation
        of the transactions contemplated hereby will (i) conflict with or
        result in a violation, breach, termination or acceleration of, or
        default under (or would result in a violation, breach,
        termination, acceleration or default with the giving of notice or
        passage of time, or both) any of the terms, conditions or
        provisions of the Certificate of Incorporation or By-laws of THS,
        as amended, or of any note, bond, mortgage, indenture, license,
        agreement or other instrument or obligation to which THS is a
        party or by which THS or any of its properties or assets may be
        bound or affected; (ii) result in the violation of any order,
        writ, injunction, decree, statute, rule or regulation applicable
        to THS or any of its properties or assets; or (iii) result in the
        imposition of any lien, encumbrance, charge or claim upon any of
        its assets.  Except for the listing of the THS Shares for trading
        on the AMEX, no consent or approval by, or notification to or
        filing with, any court, governmental authority or third party is
        required in connection with the execution, delivery and
        performance of this Agreement by THS or the consummation of the
        transactions contemplated hereby.   The THS Shares will be, when
        issued in accordance with this Agreement, duly authorized,
        validly issued, fully paid, nonassessable and free of pre-emptive
        rights.

             3.3  Statements True and Correct.  The statements contained
        herein or in any written documents prepared and delivered by or
        on behalf of THS pursuant to the terms hereof are true, complete
        and correct in all material respects, and such documents do not
        omit any material fact required to be stated herein or therein or
        necessary to make the statements contained herein or therein not
        misleading.
                                    15PAGE
<PAGE>

        SECTION 4 - COVENANTS AND AGREEMENTS
                                       
             4.1  Conduct of Business.  Except with the prior written
        consent of THS, which will not be unreasonably withheld or
        delayed, and except as otherwise contemplated herein, during the
        period from the date hereof to the Closing Date, THI shall cause
        the Sellers and the Company to observe the following covenants:

                  (a)  Affirmative Covenants Pending Closing.  The
        Sellers and the Company shall:

                       (i)  Preservation of Personnel.  Use all
        reasonable efforts to preserve intact the business organization
        of the Company and keep available the services of the present
        employees of the Company, in each case in accordance with past
        practice, it being understood that the termination of employees
        with poor performance ratings shall not constitute a violation of
        this covenant;

                       (ii) Insurance.  Use all reasonable efforts to
        keep in effect casualty, public liability, worker's compensation
        and other insurance policies applicable to the Company in
        coverage amounts not less than those in effect at the date of
        this Agreement;

                       (iii)     Preservation of the Business;
        Maintenance of Properties.  Use all reasonable efforts to
        preserve the business of the Company, advertise, promote and
        market its products and services in accordance with past
        practices over the last twelve months, keep their properties
        intact, preserve their goodwill, maintain all physical properties
        in such operating condition as will permit the conduct of such
        business on a basis consistent with past practice;

                       (iv) Intellectual Property Rights.  Use all
        reasonable efforts to preserve and protect the Proprietary Rights
        of the Company; and

                       (v)  Ordinary Course of Business.  Operate the
        business of the Company solely in the ordinary course.

                  (b)  Negative Covenants Pending Closing.  THI shall
        cause each of the Sellers and the Company not to:

                       (i)  Disposition of Assets.  Sell or transfer, or
        mortgage, pledge or create or permit to be created any lien on,
        any of the assets of the Company other than sales or transfers in
        the ordinary course of business or the creation of liens under
        existing arrangements disclosed hereunder and liens permitted
        under Section 2.8;

                       (ii) Liabilities.  Permit the Company to (A) incur
        any obligation or liability other than in the ordinary course of
        business, (B) incur any indebtedness for borrowed money in excess
        of $100,000 or (C) enter into any contracts or commitments
                                       16PAGE
<PAGE>
        involving payments by the Company of $100,000 or more other than
        purchase orders and commitments for inventory, materials and
        supplies in the ordinary course of business;

                       (iii)     Compensation.  Except as required by
        applicable law or any existing employment or severance agreement,
        (A) change the compensation or fringe benefits of any officer,
        director, employee or agent of the Company, except for ordinary
        merit increases for employees other than officers based on
        periodic reviews in accordance with past practices, or (B) enter
        into or modify any employment, severance or other agreement with
        any officer, director or employee of the Company or any benefit
        plan (it being understood that hiring of at will employees in the
        ordinary course of business shall not constitute a violation of
        this covenant) or (C) enter into or modify any agreement with any
        consultant, except for agreements terminable upon not more than
        one year's notice that are consistent with past practices with
        respect to consulting agreements.

                       (iv) Capital Stock.  Make any change in the number
        of shares of capital stock of the Company authorized, issued or
        outstanding or grant any option, warrant or other right to
        purchase, or to convert any obligation into, shares of capital
        stock of the Company, or declare or pay any dividend or other
        distribution with respect to any shares of  capital stock of the
        Company, or sell or transfer any shares of its capital stock;

                       (v)  Organizational Documents.  Amend the
        organizational documents of the Company;

                       (vi) Acquisitions.  Make any material acquisition
        of property other than in the ordinary course of the business of
        the Company;

                       (vi) License Agreements.  Enter into or modify any
        license, technology development or technology transfer agreement
        between any of the Company and any other person or entity.

             4.2  Corporate Examinations and Investigations.  Prior to
        the Closing Date, THS shall be entitled, through its employees
        and representatives, to have such access to the assets,
        properties, business and operations of the Company, as is
        reasonably necessary or appropriate in connection with its
        investigation of the Company with respect to the transaction
        contemplated hereby.  Any such investigation and examination
        shall be conducted at reasonable times and under reasonable
        circumstances so as to minimize any disruption to or impairment
        of the business and each party shall cooperate fully therein.  No
        investigation by THS shall diminish or obviate any of the
        representations, warranties, covenants or agreements of THI
        contained in this Agreement.  In order that THS may have full
        opportunity to make such investigation, THI shall furnish the
        representatives of THS with all such information and copies of
        such documents concerning the affairs of the Company as THS may
                                       17PAGE
<PAGE>
        reasonably request and cause its officers, employees,
        consultants, agents, accountants and attorneys to cooperate fully
        with THS's representatives in connection with such investigation.

             4.3  Expenses.  THS and THI shall bear their respective
        expenses incurred in connection with the preparation, execution
        and performance of this Agreement and the transactions
        contemplated hereby, including without limitation, all fees and
        expenses of agents, representatives, counsel and accountants.

             4.4  Authorization from Others.  Prior to the Closing Date,
        the parties shall use all reasonable efforts to obtain all
        authorizations, consents and permits of others required to permit
        the consummation of the transactions contemplated by this
        Agreement.

             4.5  Consummation of Agreement.  Each party shall use all
        reasonable efforts to perform and fulfill all conditions and
        obligations to be performed and fulfilled by it under this
        Agreement and to ensure that to the extent within its control or
        capable of influence by it, no breach of any of its respective
        representations, warranties and agreements hereunder occurs or
        exists on or prior to the Closing Date, all to the end that the
        transactions contemplated by this Agreement shall be fully
        carried out in a timely fashion.

             4.6  Further Assurances.  Each of the parties shall execute
        such documents, further instruments of transfer and assignment
        and other papers and take such further actions as may be
        reasonably required or desirable to carry out the provisions
        hereof and the transactions contemplated hereby. 

             4.7  Listing of Shares.  Promptly after the date hereof, THS
        shall take all action necessary in accordance with applicable law
        to convene a meeting of its shareholders to be held for the
        purpose of approving the listing of the THS Shares for trading
        upon AMEX in accordance with Section 712 of AMEX's Listing
        Standards, Policies and Requirements.  In connection with such
        meeting, THS's Board of Directors shall recommend to the THS
        shareholders the approval of the listing of the THS Shares
        pursuant to this Agreement.  THS shall use all reasonable efforts
        to obtain all votes and approvals of the THS shareholders
        necessary for the listing of the THS Shares and all related
        matters required under the Delaware Business Corporation Act, and
        its Certificate of Incorporation and By-laws.  THI hereby agrees
        to vote all of the shares of THS common stock held by it as of
        the record date of any such meeting in favor of the listing of
        the THS Shares and all such related matters.

             4.8  Public Announcements and Confidentiality.  Any press
        release or other information to the press or any third party with
        respect to this Agreement or the transactions contemplated hereby
        shall require the prior approval of THS and THI, which approval
        shall not be unreasonably withheld, provided that a party shall
                                       18PAGE
<PAGE>
        not be prevented from making such disclosure as it shall be
        advised by counsel is required by law.

             4.9  No Solicitation.  None of the Sellers or the Company
        will (i) solicit or initiate discussions with any person, other
        than THS, relating to the possible acquisition of any of the
        Company or all or a material portion of the assets or any of the
        capital stock of the Company or any merger or other business
        combination with the Company (an "Acquisition Transaction") or
        (ii) except to the extent reasonably required by fiduciary
        obligations under applicable law as advised by legal counsel,
        participate in any negotiations regarding, or furnish to any
        other person information with respect to, any effort or attempt
        by any other person to do or to seek any Acquisition Transaction.
        THI agrees to inform THS within one business day of its receipt
        of any offer, proposal or inquiry relating to any Acquisition
        Transaction.

             4.10 Indemnification. 

                  (a)  Right to Indemnification.  THS and THI (as the
        case may be, the "Indemnitee") shall be indemnified on its
        respective demand made to the other (the "Indemnitor") for the
        full amount of all damages (as defined below) suffered by it as a
        direct or indirect result of:

                       (i)  the inaccuracy of any representation or
        warranty made by the Indemnitor in or pursuant to this Agreement;
        and

                       (ii) any failure by the Indemnitor to perform any
        obligation or comply with any covenant or agreement specified in
        this Agreement.

        For the purpose of this Section 4.10, (a) the term "damages"
        shall be determined and computed by reference to the effect of
        the compensable event on the Indemnitee, and shall be deemed to
        include (i) all losses, liabilities, expenses or costs incurred
        by the Indemnitee, including reasonable attorneys' fees, and (ii)
        interest at a rate per annum equal to that announced from time to
        time by First National Bank of Boston as its "base rate" (or the
        legal rate of interest, if lower) from the date 30 days after
        notice of any such claim for indemnification is given to the
        Indemnitor, or if an unliquidated claim, from such later date as
        the claim is liquidated, to the date full indemnification is made
        therefor; and (b) damages shall not include any amounts for which
        the Indemnitee actually receives payment under an insurance
        policy, excluding self-insured amounts and deductible amounts. 

                  (b)  Indemnification Procedures.  The Indemnitee shall
        give the Indemnitor notice of any claim, action or proceeding by
        a third party which is reasonably likely to result in a claim for
        indemnification under this Section 4.10.  The Indemnitor shall
        have the right, at its expense, to defend, contest, protest,
                                       19PAGE
<PAGE>
        settle and otherwise control the resolution of any such claim,
        action or proceeding.  The Indemnitee shall have the right to
        participate in any such legal proceeding, subject to the
        Indemnitor's right of control thereof, at the expense of the
        Indemnitee and with counsel selected by the Indemnitee.

                  (c)  Limitations on Indemnification.  The rights of THS
        and THI to be indemnified pursuant to Section 4.10 shall survive
        the Closing Date for a period of two years.

             4.11 Tax-Free Qualification.  The Sellers and THS agree that
        they will take no actions not contemplated by this Agreement that
        would cause the transaction not to qualify as a tax-free
        reorganization under Section 368 of the Internal Revenue Code.

        SECTION 5 - CONDITIONS PRECEDENT TO THE OBLIGATIONS OF THS

             The obligation of THS to acquire the Shares is subject to
        the satisfaction or waiver, at or before the Closing Date, of the
        following conditions:

             5.1  Representations, Warranties and Covenants.  The
        representations and warranties of THI contained in this Agreement
        shall be true and correct in all material respects on and as of
        the Closing Date with the same force and effect as though made on
        and as of the Closing Date (with such exceptions as may be
        permitted under or contemplated by this Agreement) and there
        shall not have been any material adverse change in the business
        of the Company taken as a whole since the date hereof.  THI shall
        have performed and complied in all material respects with all
        covenants and agreements required by this Agreement to be
        performed or complied with by it on or prior to the Closing Date
        and shall have obtained all required consents and approvals.  THI
        shall have delivered to THS a certificate, dated the Closing
        Date, to the foregoing effect.

             5.2  Certificates. THI shall have furnished THS with such
        certificates of public officials and of the Sellers' or the
        Company' officers as may be reasonably requested by THS.


        SECTION 6 - CONDITIONS PRECEDENT TO THE OBLIGATION OF THI

             The obligation of THI to sell the Shares is subject to the
        satisfaction or waiver, at or before the Closing Date, of the
        following conditions:

             6.1  Representations, Warranties and Covenants.  The
        representations and warranties of THS contained in this Agreement
        shall be true and correct in all material respects on and as of
        the Closing Date with the same force and effect as though made on
        and as of the Closing Date (with such exceptions as may be
        permitted under or contemplated by this Agreement).  THS shall
        have performed and complied in all material respects with all
                                       20PAGE
<PAGE>
        covenants and agreements required by this Agreement to be
        performed or complied with by it on or prior to the Closing Date
        and shall have obtained all required consents and approvals,
        including approval of the THS shareholders of the listing of the
        THS Shares on the AMEX.  THS shall have delivered to LSI a
        certificate, dated the Closing Date, to the foregoing effect.

             6.2  Certificates.  THS shall have furnished THI with such
        certificates of public officials and of THS's officers as may be
        reasonably requested by THI.

        SECTION 7 - TERMINATION, AMENDMENT AND WAIVER

             7.1  Termination.  This Agreement may be terminated at any
        time prior to the Closing Date as follows:

                  (a)  by THI upon written notice to THS if THS has
        materially breached any representation, warranty, covenant or
        agreement contained herein and has not cured such breach within
        ten (10) business days of receipt of written notice from THI;

                  (b)  by THS upon written notice to THI if THI has
        materially breached any representation, warranty, covenant or
        agreement contained herein and has not cured such breach within
        ten (10) business days of receipt of written notice from THS;

                  (c)  by either party if any court of competent
        jurisdiction or United States or foreign governmental body shall
        have issued an order, decree or ruling or taken any other action
        restraining, enjoining or otherwise prohibiting the sale of any
        of the Shares and such order, decree or ruling shall have become
        final and nonappealable; or

                  (d)  at any time with the written consent of THS and
        THI.

             7.2  Effect of Termination.  If this Agreement is terminated
        as provided in Section 7.1, this Agreement shall forthwith become
        void and have no effect, without liability on the part of any
        party, its directors, officers or stockholders, other than the
        provisions of this Section 7.2, Section 4.3 relating to expenses
        and Section 4.8 relating to publicity and confidentiality to the
        extent provided therein.  Nothing contained in this Section 7.2
        shall relieve any party from liability for any breach of this
        Agreement occurring before such termination.

             7.3  Amendment.  This Agreement may not be amended except by
        an instrument signed by each of the parties hereto.

             7.4  Waiver.  At any time, any party hereto may (a) extend
        the time for the performance of any of the obligations or other
        acts of any other party hereto or (b) waive compliance with any
        of the agreements of any other party or any conditions to its own
        obligations, in each case only to the extent such obligations,
                                       21PAGE
<PAGE>
        agreements and conditions are intended for its benefit; provided
        that any such extension or waiver shall be binding upon a party
        only if such extension or waiver is set forth in a writing
        executed by such party.

        SECTION 8 - MISCELLANEOUS

             8.1  Notices.  All notices, requests, demands, consents and
        other communications which are required or permitted hereunder
        shall be in writing, and shall be deemed given when actually
        received or if earlier, one day after deposit with a nationally
        recognized air courier or express mail, charges prepaid or three
        days after deposit in the U.S. mail by certified mail, return
        receipt requested, postage prepaid, addressed as follows:
         
                  If to THI:

                       Thermo Instrument Systems Inc.
                       1851 Central Drive
                       Suite 314
                       Bedford, TX  76021
                       Attention:  President


                  With a copy to:

                       Thermo Electron Corporation
                       81 Wyman Street
                       Waltham, Massachusetts  02254
                       Attention:  General Counsel

                  If to THS:

                       ThermoSpectra Corporation
                       81 Wyman Street
                       Waltham, Massachusetts  02254
                       Attention:  President


                  With a copy to:

                       Thermo Electron Corporation
                       81 Wyman Street
                       Waltham, Massachusetts  02254
                       Attention:  General Counsel

        or to such other address as any party hereto may designate in
        writing to the other parties, specifying a change of address for
        the purpose of this Agreement.

                                       22PAGE
<PAGE>
             8.2  Survival and Materiality of Representations.  Each of
        the representations, warranties and agreements made by the
        parties hereto shall be deemed material and shall survive the
        Closing Date and the consummation of the transactions
        contemplated hereby. All statements contained in any certificates
        or other instruments delivered by or on behalf of the parties
        pursuant hereto or in connection with the transactions
        contemplated hereby shall be deemed material and shall constitute
        representations and warranties by the person making such
        statement.

             8.3  Entire Agreement.  This Agreement, including the
        exhibits, the Disclosure Schedule and the other documents
        referred to herein, supersedes any and all oral or written
        agreements or understandings heretofore made relating to the
        subject matter hereof and constitutes the entire agreement of the
        parties relating to the subject matter hereof.

             8.4  Parties in Interest.  All covenants and agreements,
        representations and warranties contained in this Agreement made
        by or on behalf of any of the parties hereto shall bind and inure
        to the benefit of the parties hereto, and their respective
        successors, assigns, heirs, executors, administrators and
        personal representatives, whether so expressed or not.

             8.5  No Implied Rights or Remedies.  Except as otherwise
        expressly provided herein, nothing herein expressed or implied is
        intended or shall be construed to confer upon or to give any
        person, firm or corporation, other than the parties hereto, any
        rights or remedies under or by reason of this Agreement.

             8.6  Headings.  The headings in this Agreement are inserted
        for convenience of reference only and shall not be a part of or
        control or affect the meaning hereof.

             8.7  Severability.  If any provision of this Agreement shall
        be declared void or unenforceable by any judicial or
        administrative authority, the validity of any other provision
        shall not be affected thereby.

             8.8  Counterparts.  This Agreement may be executed in
        several counterparts, each of which shall be deemed an original,
        but all of which together shall constitute one and the same
        instrument.

             8.9  Further Assurances. THI will execute and furnish to THS
        all documents and will do or cause to be done all other things
        that THS may reasonably request from time to time in order to
        give full effect to this Agreement and to effectuate the intent
        of the parties.

             8.10 Governing Law.  This Agreement shall be governed by the
        law of the State of Delaware applicable to agreements made and to

                                       23PAGE
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        be performed wholly within such jurisdiction, without regard to
        the conflicts of laws provisions thereof.

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             IN WITNESS WHEREOF, the parties have caused this Agreement
        to be duly executed as of the date first written above.

                                      THERMOSPECTRA CORPORATION



        [Seal]                        By:/s/ Theo Melas-Kyriazi   
                                      Name:     Theo Melas-Kyriazi
                                      Title:    President


                                      THERMO INSTRUMENT SYSTEMS INC.



        [Seal]                        By:/s/ Earl R. Lewis        
                                      Name:     Earl R. Lewis
                                      Title:    President




        AA972030008