Exhibit 2


                              SHARE PURCHASE AGREEMENT

                                      BETWEEN

                              THERMO OPTEK 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 Thermo Optek Corporation ("TOC"), 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 "Spectronic Shares") of Spectronic Instruments Inc.
        ("Spectronic"), a corporation organized under the laws of the
        State of Delaware.  THI also owns, directly or through
        wholly-owned subsidiaries, all of the issued and outstanding
        shares (the "VG Shares") of VG Systems Limited ("VG"), a private
        limited liability company organized under the laws of the United
        Kingdom.  The Spectronic Shares and the VG Shares are referred to
        collectively as the "Shares".  THI, LSI and those of THI's and
        LSI's wholly-owned subsidiaries that own Shares are referred to
        individually as a "Seller" and collectively as the "Sellers".
        Spectronic and VG are referred to collectively as the "Companies"
        and individually as a "Company".

             2.   TOC 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 delivery to TOC, or its wholly-owned
        subsidiaries, and TOC or its wholly-owned subsidiaries shall
        purchase, acquire and accept the Shares.

             1.2  Further Assurances.   At any time and from time to time
        after the Closing, at TOC'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 TOC may

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        reasonably request, more effectively to transfer, convey and
        assign to TOC, and to confirm TOC's title to, all of the Shares
        owned by such Seller, to put TOC in actual possession and
        operating control of the assets, properties and business of the
        Companies, 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 TOC for the
        Spectronic Shares (the "Spectronic Purchase Price") shall consist
        of (i) $20,745,450 in cash and (ii) 1,000 shares of common stock
        of TOC (the "TOC Shares").

                  (b)  TOC and THI acknowledge and agree that the
        Spectronic Purchase Price represents an estimate of the sum of
        (i) the net operating assets of Spectronic 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 Spectronic 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
        Spectronic (the "Spectronic Net Asset Statement"), and a draft
        calculation of THI's total goodwill associated with the
        acquisition of LSI (the "THI Goodwill Statement") in each case as
        of June 28, 1997.  TOC will review such statements and provide
        THI with any objections thereto within 30 days after TOC's
        receipt thereof.  If TOC does not object within such 30-day
        period, then the THI Goodwill Statement and the Spectronic Net
        Asset Statement shall be deemed to be accepted by TOC and shall
        become final.  If TOC 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 TOC
        and THI and the statements shall be finalized in accordance with
        the determination of such firm.  Upon finalization of the
        Spectronic Net Asset Statement and the THI Goodwill Statement as
        provided above, the Spectronic Purchase Price shall be increased
        or decreased, as the case may be,  by (A) the amount by which the
        net operating assets of Spectronic as shown on the Spectronic Net
        Asset Statement are greater than or less than $14,686,000 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 $28,303,000.  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 June 28, 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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                  (c)  The purchase price to be paid by TOC for the VG
        Shares (the "VG Purchase Price") shall consist of $45,546,000 in
        cash. 

                  (d)  TOC and THI acknowledge and agree that the VG
        Purchase Price represents an estimate of the sum of (i) THI's
        investment in VG plus (ii) the cumulative retained earnings of VG
        for the period commencing on March 29, 1996 (the date of THI's
        acquisition of VG as part of the acquisition by THI and its
        subsidiaries of certain businesses of Fisons plc (the "Fisons
        Businesses") pursuant to the Amended and Restated Asset and Stock
        Purchase Agreement dated as of March 29, 1996 among THI, Thermo
        Electron Corporation and Fisons plc (the "Restated Agreement"),
        and ending as of June 28, 1997.  THI and TOC further acknowledge
        and agree that the purchase price paid by THI for the Fisons
        Businesses is subject to a post-closing adjustment based on the
        difference between the value of the net tangible assets of the
        Fisons Businesses as shown on the closing balance sheet dated as
        of March 29, 1996 (the "Fisons Closing Balance Sheet") and the
        target net tangible asset value provided for in the Restated
        Agreement.  In the event of any such adjustment, the VG Purchase
        Price shall be recalculated to account for any adjustment in
        THI's investment in VG.  If any such recalculation results in an
        increase in the VG Purchase Price, TOC shall pay the amount of
        such increase to THI, and if any such recalculation results in a
        decrease in the VG Purchase Price, THI shall pay the amount of
        such decrease to TOC.  

                  (e)  Any payment due by TOC or THI to the other under
        Section 1.3(b) and/or 1.3(d) shall be accompanied by interest
        from the date hereof at a rate equal to the Commercial Paper
        Composite Rate plus 25 basis points.  

             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 TOC shall deliver the
        Spectronic Purchase Price (including the TOC Shares) and the VG
        Purchase Price to THI or to such of its subsidiaries as may be
        Sellers, together with interest from June 29, 1997, accrued at a
        rate equal to the 90-day Commercial Paper Deposit Rate plus 25
        basis points, set as of June 29, 1997 and at the beginning of
        each fiscal quarter thereafter.

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        SECTION 2 - REPRESENTATIONS AND WARRANTIES OF THI

             Except as set forth on the disclosure schedule delivered to
        TOC on the date hereof (the "Disclosure Schedule"), THI
        represents and warrants to TOC 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 Companies 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 Companies 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 Companies 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
        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 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 Companies; or (iv)
        entitle any employee of any of the Companies 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

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        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 Companies is
        set forth on Exhibit A hereto.  With respect to each Company, the
        Seller set forth opposite the name of such Company on Exhibit A
        is the record and beneficial owner of all of the issued and
        outstanding shares of such Company.  All of the Shares are duly
        authorized and are validly issued, fully paid, nonassessable and
        free of preemptive rights. 

                  (b)  Except as set forth on Exhibit A, there are not
        any 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 Companies and the jurisdiction in which each
        is incorporated.  All shares of the capital stock of each
        Subsidiary owned by the Companies 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 any Company contained herein shall be
        deemed to mean such Company and each of its Subsidiaries, both
        separately and together as a consolidated whole, unless and
        except to the extent expressly indicated otherwise.

                  (b)  There are not any other shares of capital stock of
        any Subsidiary 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 Subsidiary of any Company to issue,
        transfer, sell, repurchase or redeem any shares of its capital
        stock or other securities.  There are no shareholder agreements,

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        voting trusts, proxies or other agreements, instruments or
        understandings with respect to the voting of the capital stock of
        any Subsidiary of any Company.

                  (c)  Except for its Subsidiaries, none of the
        Companies, directly or indirectly, owns any material equity
        interest in any corporation, partnership, joint venture or other
        entity.

             2.5  Financial Statements.  THI has delivered to TOC prior
        to the execution of this Agreement true and complete copies of:
        the unaudited consolidated balance sheets of each of the
        Companies as at June 28, 1997 (with respect to each Company, the
        "Balance Sheet"), and the unaudited consolidated statements of
        earnings of each of the Companies for the six-month period ended
        June 28, 1997 (collectively, with respect to each Company, the
        "Financial Statements").  The Financial Statements have been
        prepared from, and are in accordance with, the books and records
        of LSI or Fisons, as the case may be, and fairly present the
        financial condition, results of operations, and cash flows of the
        Companies as at the dates and for the periods indicated, in each
        case in accordance with U.K. 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 its respective Balance Sheet, none
        of the Companies had any 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 such
        Balance Sheet that were not adequately reflected or reserved
        against on the such Balance Sheet.  None of the Companies has any
        liabilities of the type required to be reflected or disclosed on
        a balance sheet in accordance with U.K. generally accepted
        accounting principles, other than liabilities (i) adequately
        reflected or reserved against on its respective Balance Sheet,
        (ii) incurred since the date of such 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 Companies taken as a whole, or (iv) disclosed in
        this Agreement.  None of the Companies has any 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 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, such Company.

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             2.7  Taxes.  Each of the Companies 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 Companies for Taxes have
        not been fully discharged, adequate reserves have been
        established on its respective Balance Sheet.  None of the
        federal, state, local, provincial or foreign Tax returns of the
        Companies 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.  None of the
        Companies is 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
        Companies and the Sellers, threatened, against any of the
        Companies for past due Taxes.  All Taxes incurred but not yet due
        have been fully accrued on the books of the Companies or full
        reserves have been established therefor; the reserves indicated
        on the respective Balance Sheets are also adequate to cover all
        Taxes that may become payable by the Companies in future periods
        in respect of any transactions or sales occurring on or prior to
        the date of the Balance Sheets.  Without limiting the generality
        of the foregoing, the Companies have 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.  Each Company owns and has good title to
        all of the assets and properties reflected as owned by it on its
        respective Balance Sheet or acquired by such Company since the
        date of such Balance Sheet (except personal property sold or
        otherwise disposed of in the ordinary course of business since
        the date of such Balance Sheet), free and clear of any lien,
        claim or other encumbrance, except for (i) the liens, claims or
        other encumbrances reflected on such 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 such
        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
        Companies taken as a whole.  The Companies own or have a valid
        leasehold interest in all of the buildings, structures, leasehold
        improvements, equipment and other tangible property material to
        the Companies taken as a whole, all of which are in good and
        sufficient operating condition and repair, ordinary wear and tear
        excepted and none of the Companies has received any notice that
        any such property is in violation in any material respect of any

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        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 any of the Companies during the period of
        such Company's ownership or lease that could have a material
        adverse effect on the Companies 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 Companies 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 TOC copies of
        all documents concerning any environmental or health and safety
        matter that could have a material adverse effect on the Companies
        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 Companies shown on the Balance Sheets and all accounts and
        notes receivable acquired by the Companies subsequent to the date
        of the Balance Sheets 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 Sheets with respect to the
        accounts and notes receivable shown thereon, or set up consistent
        with past practice on the books of the Companies with respect to
        the accounts and notes receivable acquired subsequent to the date
        of the Balance Sheets.

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             2.11 Inventories.  All Inventories (as defined below) of the
        Companies 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 Companies taken as a whole.  Items
        included in such Inventories are carried on the books of the
        Companies, and are valued on the Balance Sheets, 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 Companies 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 the Companies for
        manufacturing, assembly, processing, finishing, sale or resale to
        others, from time to time in the ordinary course of business of
        the Companies 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 any of the Companies are in excess of the normal,
        ordinary and usual requirements of such Company, and the
        aggregate of the contract prices to which the Companies have
        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 any of the
        Companies obligates such 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 Companies taken as a whole. There are no material
        suppliers to any of the Companies 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 Companies have all
        governmental permits, licenses, franchises, concessions, zoning
        variances and other approvals, authorizations and orders
        (collectively "Permits") material to the Companies taken as a
        whole.  All such Permits are presently in full force and effect,
        the Companies are 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 Companies, 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 Companies 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 present manner, and no new requirements pertaining to the
        manner of operating its business have been issued or announced by

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        any governmental authority during the past year nor are there any
        disputes pending between any of the Companies and any
        governmental authority relating to such Company's operations as
        presently being conducted or actively considered.

             2.14 Intellectual Property.  Each of the Companies 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 TOC. None of
        the Companies or the Sellers is aware of any claim by any third
        party that the business of any of the Companies as currently
        conducted or proposed to be conducted infringes upon the
        unlicensed Proprietary Rights of others, nor have any of the
        Companies or any of the Sellers received any notice or claim from
        any third party of such infringement by any of the Companies.
        None of the Companies 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 any of the Companies.  Each
        of the Companies 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 Companies and the Sellers, none of the
        activities of the employees of any of the Companies on behalf of
        such 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 Companies taken as a
        whole.

             2.15 Insurance.  None of the Companies is in default with
        respect to any provisions of any policy of general liability,
        fire, title or other form of insurance held by it, each of the
        Companies is current in the payment of all premiums due on such
        insurance and none of the Companies has 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 Companies maintain
        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 TOC
        all policies of general liability, fire, title or other forms of
        insurance applicable to the Companies and a description of all

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        claims pending thereunder other than health or dental insurance
        claims.

             2.16 Employee Benefit Plans. 

                  (a)  THI has made available or furnished to TOC 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 Companies (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 TOC 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 Companies 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,
        none of the Companies has any 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)  None of the Companies has any liability under or
        with respect to any employee benefit plans or arrangements that
        it no longer maintains or in which it no longer participates.

                                       11PAGE
<PAGE>
             2.17 Agreements and Documents.  THI has previously furnished
        or made available to TOC 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 any of the
        Companies;

                  (b)  (i) each agreement of any of the Companies made in
        the ordinary course of business which involves aggregate future
        payments by or to any of the Companies 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 any of the Companies to
        compete in any line of business or with any person; and (iii)
        each agreement of any of the Companies 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 any of the Companies which may not be terminated by such
        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
        Companies (or applying to any of the Companies) 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 any of the Companies, and all collective
        bargaining agreements of any of the Companies 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 any of the
        Companies (or a guarantee by any of the Companies of
        indebtedness) is or may be issued; and

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

                  None of the Companies is a party to any oral contract
        or agreement which would be required to have been furnished or
        made available to TOC under this Section 2.17 had such contract
        or agreement been committed to writing.

                                       12PAGE
<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 any of the Companies) 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 Sheets there
        has not been:

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

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

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

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

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

                  (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 any of the Companies;

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

                  (h)  any mortgage, lien, attachment, pledge,
        encumbrance or security interest created on any asset, tangible
        or intangible, of any of the Companies, or assumed, either by any
        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 reflected in this Agreement)

                                       13PAGE
<PAGE>
        engaged in, by any of the Companies, except those in the ordinary
        course 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 any of the Companies, except items included in
        current liabilities shown on the Balance Sheets and current
        liabilities incurred since the date of the Balance Sheets 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 any of the Companies, except
        in the ordinary course of business, or any sale, assignment,
        lease, transfer or other disposition of any 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 any of the Companies;

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

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

             2.20 Litigation or Proceedings.  None of the Companies is
        engaged in, or a party to, or, to the best of the Sellers' and
        the Companies' 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 any of the Companies is a
        party by or with any court, arbitrator or governmental authority
        affecting the Companies.

             2.21 Compliance with Laws.  Each 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 Companies, none is threatened, alleging that such 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 such Company (whether leased or

                                       14PAGE
<PAGE>
        owned) by condemnation or right of eminent domain and, to the
        best knowledge of the Sellers and the Companies, 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 Companies taken as a whole.

             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 Companies, threatened against any of the Companies or between
        any of the Companies 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 any of the
        Companies.  None of the products of any of the Companies 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
        Companies has employed any broker, agent or finder or incurred
        any liability on behalf of any of the Sellers or the Companies or
        for any brokerage fees, agents' commissions or finders' fees in
        connection with the transactions contemplated hereby.

             2.25 Powers of Attorney.  None of the Companies has any
        powers of attorney or similar authorizations outstanding.

             2.26 No Termination of Relationship.  As of the date hereof,
        none of the Sellers or the Companies has any reason to expect
        that any relationship between any 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.  TOC has been furnished in writing
        prior to the execution of this Agreement all information as to
        the business of the Companies 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.

                                       15PAGE
<PAGE>
        SECTION 3 - REPRESENTATIONS AND WARRANTIES OF TOC

             TOC represents and warrants to THI as follows.

             3.1  Organization.   TOC 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. TOC 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 TOC.  This Agreement has been duly and validly executed and
        delivered by TOC and constitutes the valid and binding obligation
        of TOC, 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 TOC, as amended, or of any note,
        bond, mortgage, indenture, license, agreement or other instrument
        or obligation to which TOC is a party or by which TOC 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 TOC 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 TOC 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
        TOC or the consummation of the transactions contemplated hereby.
         The TOC 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 TOC 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.
                                      16PAGE
<PAGE>

        SECTION 4 - COVENANTS AND AGREEMENTS
                                      
             4.1  Conduct of Business.  Except with the prior written
        consent of TOC, 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 Companies to observe the following covenants:

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

                       (i)  Preservation of Personnel.  Use all
        reasonable efforts to preserve intact the business organization
        of each Company and keep available the services of the present
        employees of each 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 Companies 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 Companies, 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 Companies; and

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

                  (b)  Negative Covenants Pending Closing.  THI shall
        cause each of the Sellers and the Companies 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 any of the Companies 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 any of the Companies 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 involving payments by any of the Companies of

                                       17PAGE
<PAGE>
        $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 any of the Companies, 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 any of the Companies 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 any of the Companies
        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 any of the Companies, or declare or
        pay any dividend or other distribution with respect to any shares
        of  capital stock of any of the Companies, or sell or transfer
        any shares of its capital stock;

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

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

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

             4.2  Corporate Examinations and Investigations.  Prior to
        the Closing Date, TOC shall be entitled, through its employees
        and representatives, to have such access to the assets,
        properties, business and operations of the Companies, as is
        reasonably necessary or appropriate in connection with its
        investigation of the Companies 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 TOC shall diminish or obviate any of the
        representations, warranties, covenants or agreements of THI
        contained in this Agreement.  In order that TOC may have full
        opportunity to make such investigation, THI shall furnish the

                                       18PAGE
<PAGE>
        representatives of TOC with all such information and copies of
        such documents concerning the affairs of the Companies as TOC may
        reasonably request and cause its officers, employees,
        consultants, agents, accountants and attorneys to cooperate fully
        with TOC's representatives in connection with such investigation.

             4.3  Expenses.  TOC 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  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 TOC and THI, which approval
        shall not be unreasonably withheld, provided that a party shall
        not be prevented from making such disclosure as it shall be
        advised by counsel is required by law.

             4.8  No Solicitation.  None of the Sellers or the Companies
        will (i) solicit or initiate discussions with any person, other
        than TOC, relating to the possible acquisition of any of the
        Companies or all or a material portion of the assets or any of
        the capital stock of any of the Companies or any merger or other
        business combination with any of the Companies (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 TOC within one business day of

                                       19PAGE
<PAGE>
        its receipt of any offer, proposal or inquiry relating to any
        Acquisition Transaction.

             4.9  Indemnification. 

                  (a)  Right to Indemnification.  TOC 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 4.9, (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 4.9.  The Indemnitor shall
        have the right, at its expense, to defend, contest, protest,
        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 TOC
        and THI to be indemnified pursuant to Section 4.9 shall survive
        the Closing Date for a period of two years.

             4.10 Listing of Shares.  Promptly after the date hereof, TOC
        shall take all action necessary to list the TOC Shares for
        trading upon the American Stock Exchange ("AMEX").

                                       20PAGE
<PAGE>
        SECTION 5 - CONDITIONS PRECEDENT TO THE OBLIGATIONS OF TOC

             The obligation of TOC 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 Companies 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 TOC a certificate, dated the Closing
        Date, to the foregoing effect.

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


        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 TOC 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).  TOC 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,
        including approval of the listing of the TOC Shares on the AMEX.
        TOC shall have delivered to LSI a certificate, dated the Closing
        Date, to the foregoing effect.

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

                                       21PAGE
<PAGE>
        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 TOC if TOC 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 TOC 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 TOC;

                  (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 TOC 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 4.7 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,
        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

                                       22PAGE
<PAGE>
        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, Texas  76021
                       Attention:  President

                  With a copy to:

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

                  If to TOC:

                       Thermo Optek Corporation
                       8 East Forge Parkway
                       Franklin, MA 02038
                       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.

             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.

                                       23PAGE
<PAGE>
             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 TOC
        all documents and will do or cause to be done all other things
        that TOC 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
        be performed wholly within such jurisdiction, without regard to
        the conflicts of laws provisions thereof.



        [REMAINDER OF PAGE INTENTIONALLY BLANK]

                                       24PAGE
<PAGE>

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

                                      THERMO OPTEK CORPORATION


        [Seal]                        By:  /s/ Robert J. Rosenthal
                                           ---------------------------
                                      Name:     Robert J. Rosenthal
                                      Title:    Senior Vice President



                                      THERMO INSTRUMENT SYSTEMS INC.


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