SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, DC 20549
            ----------------------------------------------------

                                 FORM 10-K

(mark one)
[ X ] Annual Report Pursuant to Section 13 or 15(d) of the Securities
      Exchange Act of 1934 for the fiscal year ended January 2, 1999

[   ] Transition Report Pursuant to Section 13 or 15(d) of the
      Securities Exchange Act of 1934

                       Commission file number 1-9567

                              THERMEDICS INC.
           (Exact name of Registrant as specified in its charter)

Massachusetts                                                    04-2788806
(State or other jurisdiction of          (I.R.S. Employer Identification No.)
incorporation or organization)

470 Wildwood Street, P.O. Box 2999
Woburn, Massachusetts                                            01888-1799
(Address of principal executive offices)                         (Zip Code)

     Registrant's telephone number, including area code: (781) 622-1000

        Securities registered pursuant to Section 12(b) of the Act:

  Title of each class            Name of each exchange on which registered
----------------------------     -----------------------------------------
Common Stock, $.10 par value              American Stock Exchange

        Securities registered pursuant to Section 12 (g) of the Act:
                                    None

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the Company was
required to file such reports), and (2) has been subject to the filing
requirements for at least the past 90 days.
Yes [ X ]  No [     ]

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of the Registrant's knowledge, in definitive proxy or information
statements incorporated by reference into Part III of this Form 10-K or any
amendment to this Form 10-K. [ ]

The aggregate market value of the voting stock held by nonaffiliates of the
Registrant as of January 29, 1999, was approximately $95,552,000.

As of January 29, 1999, the Registrant had 41,696,696 pro forma shares of common
stock outstanding.

                    DOCUMENTS INCORPORATED BY REFERENCE

Portions of the Registrant's Annual Report to Shareholders for the year ended
January 2, 1999, are incorporated by reference into Parts I and II.

Portions of the Registrant's definitive Proxy Statement for the Annual Meeting
of Shareholders to be held on May 27, 1999, are incorporated by reference into
Part III.

<PAGE>


                                   PART I
                                     
Item 1.                                               Business

(a) General Development of Business

    The businesses of Thermedics Inc. (the Company or the Registrant)
operate in four reportable segments:  Quality Assurance and Security
Products, Precision Weighing and Inspection Equipment, Heart Assist and
Blood Testing Devices, and Power Electronics and Test Equipment.

    Through the Company's Thermedics Detection Inc. subsidiary, the Quality
Assurance and Security Products segment develops, manufactures, and markets
high-speed, detection and measurement instruments used in a variety of on-line
industrial process applications, security applications, and for laboratory
analysis. On May 6, 1998, Thermedics Detection acquired Thermedics' Orion
laboratory products division in exchange for the right to receive 5,961,225
shares of Thermedics Detection common stock. Orion manufactures electrochemistry
systems that determine the quality of a wide variety of substances, including
food, cosmetics, and household products by measuring components such as pH,
specific ion concentration, dissolved oxygen, and conductivity. The issuance of
the 5,961,225 shares of Thermedics Detection common stock issuable in the merger
was approved by the January 1999 vote of Thermedics Detection shareholders.

    The Company's Precision Weighing and Inspection Equipment segment includes
the Company's Thermo Sentron Inc. subsidiary, which develops, manufactures, and
markets high-speed precision-weighing and inspection equipment for industrial
production and packaging lines.

    The Heart Assist and Blood Testing Devices segment consists of the Company's
Thermo Cardiosystems Inc. subsidiary, which has developed two implantable left
ventricular-assist systems (LVAS): a pneumatic, or air-driven, system and an
electric version. Thermo Cardiosystems' International Technidyne Corporation
subsidiary is a leading manufacturer of near-patient, whole-blood coagulation
testing equipment and related disposables and also manufactures premium-quality,
single-use skin-incision devices.

    The Power Electronics and Test Equipment segment, through the Company's
Thermo Voltek Corp. subsidiary, designs, manufactures, and markets a range of
products related to power amplification, conversion, and quality and
electronics-test instruments. On March 31, 1998, the Company proposed to
acquire, through a merger, all of the outstanding shares of common stock of
Thermo Voltek that the Company does not own, other than shares owned by Thermo
Electron, at a price of $7.00 per share in cash. A meeting of Thermo Voltek's
shareholders will occur on March 25, 1999, to consider this matter. The proposed
merger is discussed in Note 16 to Consolidated Financial Statements in the
Registrant's Fiscal 1998* Annual Report to Shareholders, which information is
incorporated herein by reference.

    In addition, the Company develops, manufactures, and markets enteral
nutrition-delivery systems and a line of medical-grade polymers used in medical
disposables and in nonmedical, industrial applications, including safety glass
and automotive coatings.

    The Company was incorporated in 1983 under the laws of Massachusetts as a
wholly owned subsidiary of Thermo Electron. On February 5, 1998, the Company's
Board of Directors voted to issue 4,880,533 shares of its common stock to Thermo
Electron in exchange for 3,355,705 shares of Thermo Cardiosystems' common stock.
The Company's issuance of the 4,880,533 shares of its common stock to Thermo
Electron is subject to approval by the Company's shareholders at a meeting to
occur on March 31, 1999. However, because Thermo Electron is the majority
shareholder and intends to vote its shares in favor of the transaction, approval
is assured. The shares of common stock will be exchanged at their respective
fair market values as of February 5, 1998. As of January 2, 1999, on a pro forma
--------------------
* References to 1998, 1997, and 1996 herein are for the fiscal years ended
  January 2, 1999, January 3, 1998, and December 28, 1996, respectively.


                                       2
<PAGE>
basis, assuming the completion of the transaction discussed above, Thermo
Electron owned 30,850,049 shares of the Company's common stock, representing 74%
of such stock outstanding. Thermo Electron is a world leader in monitoring,
analytical, and biomedical instrumentation; biomedical products including
heart-assist devices, respiratory-care equipment, and mammography systems; and
paper recycling and papermaking equipment. Thermo Electron also develops
alternative-energy systems and clean fuels, provides a range of services
including industrial outsourcing and environmental-liability management, and
conducts research and development in advanced imaging, laser, and electronic
information-management technologies.

    Thermo Electron intends, for the foreseeable future, to maintain at least
50% ownership of the Company. This may require Thermo Electron to purchase
additional shares of the Company's common stock (or debentures convertible into
common stock) from time to time, as the number of the Company's outstanding
shares increases. These or any other purchases may be made either in the open
market or directly from the Company. See Notes 4 and 7 to Consolidated Financial
Statements in the Company's 1998 Annual Report to Shareholders for a description
of the Company's outstanding stock options and convertible debentures. During
1998, Thermo Electron purchased 4,828,895 shares of the Company's common stock
in the open market for $52.8 million. Additionally, during 1998, Thermo Electron
purchased in the open market 882,450 shares of common stock of Thermedics
Detection for $8.2 million and 454,224 shares of common stock of Thermo Sentron
for $4.3 million.

    During 1998, Thermo Electron announced a proposed reorganization involving
certain of Thermo Electron's subsidiaries, including the Company. Under this
plan, the Company may acquire Thermo Electron's wholly owned biomedical group
for shares of Company common stock and the Company's equity interest in its
Thermo Sentron, Thermedics Detection, and Thermo Voltek subsidiaries. Thermo
Electron may, in turn, take Thermo Sentron and Thermedics Detection private, and
shareholders of these subsidiaries would receive cash in exchange for their
shares of common stock. The proposed transactions are subject to a number of
conditions, as outlined in Note 16 to Consolidated Financial Statements in the
Registrant's 1998 Annual Report to Shareholders, which information is
incorporated herein by reference.

Forward-looking Statements

    Forward-looking statements, within the meaning of Section 21E of the
Securities and Exchange Act of 1934, are made throughout this Annual Report on
Form 10-K. For this purpose, any statements contained herein that are not
statements of historical fact may be deemed to be forward-looking statements.
Without limiting the foregoing, the words, "believes," "anticipates," "plans,"
"expects," "seeks," "estimates," and similar expressions are intended to
identify forward-looking statements. There are a number of important factors
that could cause the results of the Company to differ materially from those
indicated by such forward-looking statements, including those detailed under the
heading "Forward-looking Statements" in the Registrant's 1998 Annual Report to
Shareholders, which statements are incorporated herein by reference.

(b) Financial Information About Segments

    Financial information concerning the Company's segments is summarized in
Note 13 to Consolidated Financial Statements in the Registrant's 1998 Annual
Report to Shareholders, which information is incorporated herein by reference.

(c) Description of Business

    (i)  Principal Products and Services


                                       3
<PAGE>
Quality Assurance and Security Products

Detection Instruments

    Thermedics Detection supplies high-speed detection and measurement systems
to examine a variety of products and substances either on-line or in a
laboratory to ensure their quality. The ALEXUS(R) systems detect trace amounts
of constituents that would affect product quality in refillable plastic beverage
containers. The InScan(R) high-speed X-ray imaging system uses high-speed X-ray
imaging technology to determine accurate fill volume, net volume, proper
contents, and package integrity of containers for the beverage, food, and other
industries. Through its Moisture Systems division, Thermedics Detection designs,
manufactures, and markets equipment that uses near-infrared spectroscopy to
measure moisture and other product constituents, including fats, proteins, oils,
flavorings, solvents, adhesives, and coatings, in a variety of products as they
move along manufacturing lines. These systems are used across the food,
pharmaceutical, chemical, petrochemical, tobacco, forest products, paper
converting, plastics, textiles, corrugating, and other industries.

    Thermedics Detection's high-speed gas chromatograph, called Flash-GC(TM),
provides information on the composition of a wide range of substances, such as
pharmaceuticals, food, and water, at speeds 20 to 50 times faster than
conventional gas chromatographs, while its EZ-Flash(TM) system is an upgrade kit
that can be integrated with virtually any conventional gas chromatograph to
enable it to conduct chemical analyses up to 30 times faster.

    Also through Thermedics Detection, the Company produces security instruments
that use trace particle- and vapor-detection techniques for forensics, search,
and screening applications under the direction of police, border police,
transportation authorities, and carriers. Thermedics Detection's principal
security instrument is the EGIS(R) system, a highly sensitive particle- and
vapor-detection system for screening people, baggage, packages, freight, and
electronic equipment such as personal computers, for the presence of a wide
range of explosives, including plastic explosives that have proven difficult to
detect using conventional methods. Currently, more than 275 EGIS units are
deployed at airports, border crossings, and other checkpoints. In addition, EGIS
units have been used in highly visible forensic investigations, including the
crash of TWA Flight 800, as well as the bombings in Oklahoma City, at New York's
World Trade Center, and at locations in Israel, Buenos Aries, and the United
Kingdom. In 1998, Thermedics Detection introduced a new line of benchtop
explosives-detection systems based on its EGIS technology. This family of
products includes the EGIS II, the more sensitive EGIS III, and the EGIS IV,
Thermedics Detection's most sensitive explosives detector to date. Thermedics
Detection also has developed SecurScan(TM), a walk-through explosives detector.

    During 1998, 1997, and 1996, the Company derived revenues of $40.3 million,
$51.3 million, and $43.8 million, respectively, from its detection instruments.

Laboratory Products

    Through its Orion subsidiary, Thermedics Detection manufactures a wide range
of electrochemistry products that determine the quality of many substances by
measuring their pH, specific ion concentration, dissolved oxygen, and
conductivity. Orion's products are used in the food, beverage, pharmaceutical,
chemical, environmental analysis, drinking water, wastewater treatment,
agricultural, biomedical research, and many other industries. Pure water
monitors, also marketed under the Orion name, use ion-selective technology to
evaluate water quality in the power, semiconductor, drinking water, and
pharmaceutical industries. Other products include microweighing equipment and
titration systems.

    During 1998, 1997, and 1996, the Company derived revenues of $51.3 million,
$53.1 million, and $50.9 million, respectively, from its laboratory products.


                                       4
<PAGE>
Precision Weighing and Inspection Equipment

    Thermo Sentron serves two principal markets: packaged goods and bulk
materials. Thermo Sentron's products for the packaged-goods market include a
broad line of checkweighing equipment and metal detectors that can be integrated
at various stages in production lines for process control and quality assurance,
as well as hot foil and thermal printers and X-ray inspection equipment. These
products are sold primarily to customers in the food-processing, pharmaceutical,
mail-order, and other diverse industries. Products in Thermo Sentron's
bulk-materials line include conveyor-belt scales, solid level-measurement and
conveyor-monitoring systems, sampling systems, and small-capacity feeders. These
products are sold primarily to customers in the mining and material-processing
industries, as well as electric utilities and chemical and other manufacturing
companies. In June 1998, Thermo Sentron acquired the three businesses that
constituted the product-monitoring group of Graseby Limited (the
product-monitoring businesses), a subsidiary of Smiths Industries plc. The
product-monitoring businesses design, manufacture, and distribute specialized
packaged-goods equipment, including checkweighers and metal detectors, for the
food and pharmaceutical industries. In February 1997, Thermo Sentron acquired
the business of RCC Industrial Electronics Pty. Limited, an Australia-based
manufacturer of in-motion checkweighers for the food and pharmaceutical
industries. In July 1997, Thermo Sentron acquired Westerland Engineering Ltd., a
U. K.-based manufacturer of process-weighing and control equipment.

Heart Assist and Blood Testing Devices

    Left Ventricular-assist Systems. The Company, through its Thermo
Cardiosystems subsidiary, has developed two versions of its LVAS: an implantable
pneumatic, or air-driven, system that can be controlled by either a bedside or
portable console; and an electric system that features an internal electric
motor powered by an external battery pack worn by the patient. Both of the
Company's systems employ the Company's HeartMate(R) blood pump, and are designed
for long-term use. This pump is implanted just below the diaphragm in a position
that minimizes interference with normal circulation and other bodily functions.
An inlet tube is inserted into the apex of the left ventricle to drain blood
into the pump chamber. Blood is then forced out of the pump through an animal
tissue valve and back into the aorta. The HeartMate blood pump works with the
biological control mechanism of the natural heart to increase pumping capability
when required for activities such as climbing stairs. The Company's LVAS are at
various stages of regulatory approval.

    Air-driven LVAS. In October 1994, the FDA approved the air-driven system as
a bridge to transplant for patients awaiting heart transplantation. This
approval allows the Company to sell the air-driven LVAS to any of the nearly 900
cardiac surgery centers in the United States. In April 1994, the Company's
air-driven LVAS received the CE Mark required for commercial sale of medical
devices in all European Community countries. In August 1998, the Medical Devices
Bureau of Health Canada issued a Notice of Compliance for the Company's
air-driven HeartMate LVAS, permitting its sale throughout Canada. In the
air-driven LVAS, the HeartMate blood pump is coupled to an external console
connected to the body by a tube. The Company has also developed the
HeartPak(TM), a lightweight portable console that can be carried over the
shoulder. The portable console received the CE Mark for commercial sale in
European Community countries in February 1995. In July 1995, the FDA approved
the beginning of clinical trials of the HeartPak portable pneumatic driver. The
Company is currently evaluating the safety of the system in the hospital, and
the Company also plans to evaluate the system in the home environment.

    Electric LVAS. The Company has also developed an electric LVAS that uses the
HeartMate blood pump driven by an internal electric motor mounted in the blood
pump housing. The system is connected to its external battery pack by wires that
exit the body. Since the power source and control elements are worn on a battery
belt, the system allows the patient complete mobility. In August 1995, the
electric LVAS received the CE Mark, allowing commercial sale of this system in
all European Community countries. The electric system is used as a bridge to
transplant in the United States, Europe, and other regions, and is also
implanted as an alternative to heart transplant in Europe and other regions. In
August 1998, the Medical Devices Bureau of Health Canada issued a Notice of
Compliance for the

                                       5
<PAGE>
Company's electric system, permitting its sale throughout Canada. In September
1998, the FDA approved the electric system for commercial sale as a bridge to
transplant for patients awaiting heart transplantation.

    In December 1995, the FDA approved the protocol for conducting clinical
trials of the electric LVAS as a long-term solution for nontransplant
candidates. The trial is expected to compare the results of approved patients
using the device to a similar number using drug therapy. In December 1997, the
FDA approved the Company's proposal to broaden the entrance criteria and
increase the number of participating sites under this trial. The Company
estimates that it will complete this trial in two to three years; however, no
assurance can be given that the Company will complete this study in this time
period or that it will receive FDA approval after the trial or at all.

    During 1998, 1997, and 1996, the Company derived revenues of $30.3 million,
$27.0 million, and $30.0 million, respectively, from its LVAS.

    Blood-testing Equipment and Skin-incision Devices. Thermo Cardiosystems'
International Technidyne subsidiary manufactures and supplies whole-blood
coagulation testing equipment and related disposables, as well as skin-incision
devices. International Technidyne's product lines offer whole-blood coagulation
systems for bedside anticoagulation management, coagulation screening, and
transfusion management. Each analyzes small blood samples, then processes and
quickly displays comprehensive patient hemostatis information. Blood management
of this type is essential for cardiopulmonary bypass surgery and angioplasty.
The ProTime(R) Microcoagulation System is designed to allow self-testing for
patients who take the blood-thinning drug warfarin (Coumadin). International
Technidyne also manufactures a family of single-use skin-incision devices for
drawing blood from adults, children, and infants.

    During 1998, 1997, and 1996, the Company derived revenues of $36.5 million,
$35.9 million, and $34.0 million, respectively, from its blood-testing equipment
and skin-incision devices.

Power Electronics and Test Equipment

    Through its Thermo Voltek subsidiary, the Company designs, manufactures, and
markets a range of products related to power amplification and conversion as
well as instruments that test electronic systems and components. The Company's
power products include radio frequency (RF) and microwave power amplifiers,
power-conversion equipment, and application-specific power supplies. These power
products are used in communications, broadcast, research, and medical imaging
applications. Thermo Voltek's test instruments simulate pulsed electromagnetic
interference, radio frequency interference, and changes in AC voltage, to allow
manufacturers of electronic systems and integrated circuits to test for
electromagnetic compatibility (EMC). These products are used in the
product-development, design-verification, and quality-assurance stages, enabling
customers to optimize performance, reliability, and safety in the final design,
and to meet industry standards and regulatory requirements, including a European
Union directive that took effect in January 1996. During 1997 and 1998, Thermo
Voltek experienced lower demand for its EMC test products, due to the declining
influence of IEC 801, the European Union directive on electromagnetic
compatibility that took effect January 1, 1996, and, to a lesser extent, a
decline in the component-reliability market for electrostatic discharge test
equipment that resulted from a slowdown in capital expenditures by the
semiconductor industry. Due in part to these developments, during 1997 and 1998
the Company implemented certain operational, organizational, and personnel
changes.

    In November 1998, Thermo Voltek sold substantially all of the assets,
excluding real property, of its Universal Voltronics division to an unrelated
buyer. The purchase price for the transferred assets was $2,500,000 in cash,
$2,250,000 of which had been received as of year-end 1998.


                                       6
<PAGE>
Other

    The Company's research relating principally to the development of its LVAS
has resulted in the development of proprietary medical-grade plastics marketed
under the names Tecoflex(R) and Tecothane(R). Tecoflex and Tecothane are
thermoplastic polyurethanes used in medical disposables and industrial products.
The Company sells Tecoflex and Tecothane in bulk form for fabrication by the
customer, and also extrudes precision tubing to customer specifications.

    The Company's Corpak Inc. subsidiary designs, manufactures, and markets
enteral feeding systems that introduce special nutritional solutions into the
stomach or the small intestine through tubes entering the nose or stomach.
Enteral therapy is used for patients who are unable to feed themselves but who
do not require parenteral (intravenous) feeding. Corpak's products include bags
for nutritional fluids, delivery pumps, associated pump sets that hook up to the
pumps, and feeding tubes. In addition, Corpak markets catheters for peritoneal
dialysis.

    (ii) and (xi) New Products; Research and Development

    The Company maintains research and development capability to support its
existing products and to develop new products. A number of programs are
underway, funded by the Company solely or jointly with an outside source. These
programs include development of new products to perform substantially all or
part of the pumping function of the left ventricle of the natural heart, quality
assurance and security instruments, electronics-test instruments, and high
voltage power supply products. The Company also develops new grades of polymers
to meet specific customer requirements for industrial and medical applications.

    During 1998, 1997, and 1996, the Company expended $26.6 million, $24.3
million, $21.4 million, respectively, on internally sponsored research and
development programs, and $4.2 million, $2.9 million, and $1.4 million,
respectively, on research and development programs sponsored by others. As of
January 2, 1999, 168 professional employees were engaged full-time in research
and development activities.

    (iii)   Raw Materials

    Certain raw materials used in the manufacture of the Company's LVAS are
available from only one or two suppliers. The Company is making efforts to
minimize the risks associated with sole sources and ensure long-term
availability, including qualifying alternative materials and components or
developing alternative sources for materials and components supplied by a single
source. Although the Company believes that it has adequate supplies of materials
and components to meet demand for the LVAS for the foreseeable future, no
assurance can be given that the Company will not experience shortages of certain
materials or components in the future that could delay shipments of the LVAS.

    The cost to the Company to evaluate and test alternative materials and
components and the time necessary to obtain FDA approval for these materials and
components are inherently difficult to determine because both time and cost are
dependent on at least two factors: the similarity of alternative materials or
components to the original materials or components, and the amount of
third-party testing that may have already been completed on alternative
materials or components. There can be no assurance that the substitution of
alternative materials or components will not cause delays in the Company's LVAS
development program or adversely affect the Company's ability to manufacture and
ship LVAS to meet demand.

    (iv)    Patents, Licenses, and Trademarks

    The Company considers its intellectual property important in the operation
and growth of its business, and its policy is to protect this property through
patents, license and confidentiality agreements, trademarks, and trade secret
protection. The Company applies for and maintains patents in the U.S. and in
foreign countries, particularly in the areas of biomedical materials, medical
products, and analytical instruments. Although some of these patent rights may
provide the Company with a competitive advantage, the Company primarily relies
on its know-how and trade secrets.


                                       7
<PAGE>
In addition, there can be no assurance that third parties will not assert claims
against the Company that the Company infringes the intellectual property rights
of such parties. The Company could incur substantial costs and diversion of
management resources with respect to the defense of any such claims, which could
have a material adverse effect on the Company's business, financial condition,
and results of operations. Furthermore, parties making such claims could secure
a judgment awarding substantial damages, as well as injunctive or other
equitable relief, which could effectively block the Company's ability to make,
use, sell, distribute, or market its products and services in the U.S. or
abroad. In the event that a claim relating to intellectual property is asserted
against the Company, the Company may seek licenses to such intellectual
property. There can be no assurance, however, that such licenses could be
obtained on commercially reasonable terms, if at all. The failure to obtain the
necessary licenses or other rights could preclude the sale, manufacture, or
distribution of the Company's products and, therefore, could have a material
adverse effect on the Company's business, financial condition, and results of
operations. Thermo Cardiosystems has received correspondence from a third party
alleging that the textured surface of the LVAS housing infringes certain patent
rights of such third party. In general, an owner of intellectual property can
prevent others from using such property without a license and is entitled to
damages for unauthorized usage. The Company has investigated the bases of the
allegation and, based on the opinion of its counsel and the Company's assessment
of the proceedings in the United States Patent and Trademark Office to date, it
believes that if it were sued on these bases, it would have meritorious
defenses. Given the inherent uncertainties in dispute resolution, however, if
the Company were sued and the outcome were unfavorable, the Company's results of
operations or financial condition could be materially adversely affected in
amounts the Company cannot reasonably estimate.

    In August 1998, Thermo Cardiosystems obtained an exclusive license to
incorporate technology developed by Sulzer Electronics Ltd. into an advanced
version of Thermo Cardiosystems' LVAS, HeartMate III. Sulzer Electronics Ltd.,
based in Switzerland, is a company within the Sulzer Corporation. HeartMate III
is a miniature centrifugal pump featuring a magnetically controlled system that
has been developed by Sulzer Electronics' Magnetics Group.

Quality Assurance and Security Devices

    The Company has certain licenses to the technology resulting from its
customer-sponsored development of the ALEXUS system. The Company's patents and
agreements have varying lives ranging from one year to approximately twenty
years, and the Company does not believe that the expiration or termination of
any one of these patents or agreements would materially affect the Company's
business.

    (v)     Seasonal Influences

    There are no significant seasonal influences on the Company's sales of its
products.

    (vi)    Working Capital Requirements

    There are no special inventory requirements or credit terms extended to
customers that would have a material adverse effect on the Company's working
capital.

    (vii)   Dependency on a Single Customer

    No customer represented 10% or more of the Company's total revenues in 1998,
1997, and 1996.



                                       8
<PAGE>
    (viii)  Backlog

The Company's backlog of firm orders at year-end 1998 and 1997 was:
<TABLE>
<CAPTION>
<S>                                                                                      <C>      <C>

(In thousands)                                                                              1998      1997
---------------------------------------------------------------------------------------- -------- ---------

Quality Assurance and Security Products                                                  $ 6,065  $  9,374
Precision Weighing and Inspection Equipment                                               14,683    13,142
Heart Assist and Blood Testing Devices                                                     1,818     2,556
Power Electronics and Test Equipment                                                       5,397    10,218
Other                                                                                      1,843     1,292
                                                                                         -------  --------

                                                                                         $29,806  $ 36,582
                                                                                         =======  ========
</TABLE>
 
    Certain of these orders are cancelable by the customer upon payment of a
cancellation charge. The Company anticipates that substantially all of the
backlog at the end of 1998 will be shipped or completed during 1999. The
decrease in backlog at the Quality Assurance and Security Products segment
resulted primarily from completion of large orders for quality-assurance and
security systems in 1998. The decrease in backlog at the Power Electronics and
Test Equipment segment resulted primarily from lower demand. The Company does
not believe the size of its backlog is necessarily indicative of intermediate or
long-term trends in its business.

    (ix)    Government Contracts

    Not applicable.

    (x)     Competition

Quality Assurance and Security Products

    The Company's quality assurance products compete with systems manufactured
by numerous companies. The Company believes, however, that these companies are
generally focused on particular niches in the process detection systems market,
only in some of which the Company competes. Competition in the markets for each
of the Company's quality assurance systems is based primarily on performance,
durability, service and, to a lesser extent, price. The Company believes that
its systems' performance and speed, as well as the Company's reputation for
developing superior new technologies and for the innovative application of
existing technologies to a variety of high-speed production environments and
product quality-assurance problems, are competitive advantages.

    In the security instrument market, the Company competes with a small number
of companies, including other makers of chemical trace detection instruments,
and, to a lesser degree, makers of enhanced X-ray detectors. Competition in this
market is based primarily on performance, including speed, accuracy, and the
range of explosives that can be detected; ease of use; service; and price. The
Company's principal competitor in the trace detection market is Barringer
Technologies Inc., a Canadian firm that has placed several trace detectors in
airport applications.

    In the laboratory products market, the Company competes with several
international companies. The Company competes on the basis of performance,
service, technology, and price. Competitors include Corning, Fisher Scientific,
Mettler-Toledo, and Beckman Coulter.

Precision Weighing and Inspection Equipment

    The Company's Thermo Sentron subsidiary encounters and expects to continue
to encounter intense competition in the sale of its products. Thermo Sentron's
principal competitors in the packaged-goods market are Ishida Scales

                                       9
<PAGE>

Mfg. Co., Ltd. and Mettler-Toledo AG. In the more fragmented bulk-materials
market, Thermo Sentron competes on a worldwide basis primarily with Carl Schenck
AG and Milltronics Corporation. Thermo Sentron believes that the principal
competitive pressures affecting the market for precision-weighing and inspection
equipment include customer service and support, quality and reliability, price,
accuracy, ease of use, distribution channels, technical features, compatibility
with customers' manufacturing processes, and regulatory approvals.

Heart Assist and Blood Testing Devices

    Left Ventricular-assist Systems. The Company is aware of one other company
that has received PMA approval from the FDA for an implantable LVAS similar to
the Company's. Also, the Company is aware of one other company that has received
commercial approval from the FDA for its cardiac-assist device. This is an
external device, positioned on the outside of the patient's chest, and is
intended for short-term use in the hospital environment. In November, this
company announced that it had received approval from the FDA for its IDE for a
portable power source. In addition, the Company is aware that a total artificial
heart is currently undergoing clinical trials. The Company is aware that other
cardiac-assist devices are in various stages of development by other companies.
The requirement of obtaining FDA approval for commercial sale of an LVAS in the
United States is a significant barrier to entry into the United States market
for these devices. There can be no assurance, however, that FDA regulations will
not change in the future, reducing the time and testing required for others to
obtain FDA approval for commercial sale. In addition, other research groups and
companies, some that have significantly greater resources than those of the
Company, are developing cardiac systems using alternative technologies or
concepts, one or more of which might prove functionally equivalent to, or more
suitable than, the Company's systems. Among products that have been approved for
commercial sale, the Company competes primarily on the basis of performance,
service capability, and price. Competition in the market for medical devices is
also significantly affected by the reimbursement policies of government and
private insurers. Any product for which reimbursement is not available from such
third-party payors will be at a significant competitive disadvantage.

    Blood-testing Equipment and Skin-incision Devices. International
Technidyne's principal competitor for the HEMOCHRON coagulation monitoring
instruments, used in the operating room and in cardiac catheterization, is the
HemoTec division of Medtronic, Inc. The Roche Group competes with the ProTime
with a blood coagulation monitor which is marketed to clinics and also for
patient self-testing. There are also several new competitors that have recently
entered the blood coagulation monitoring market. ITC's products compete
primarily on the basis of reputation, utility, and price. The skin-incision
devices compete with products offered by a number of companies including Organon
Teknika; Becton, Dickinson and Company; and Owen-Mumford. The incision devices
compete primarily on the basis of safety, quality, and reputation.

Power Electronics and Test Equipment

    The Company is a leading supplier of EMC testing equipment. There are
numerous companies worldwide that independently manufacture and market pulsed
EMC test equipment for electronic products, and several more that independently
manufacture and market component-reliability test equipment. In the market for
RF power amplifiers and programmable power amplifiers, the Company competes with
several companies worldwide. The Company competes in these markets primarily on
the basis of performance, technical expertise, reputation, and price.
Substantially all of the Company's contract and commercial revenues are subject
to intense competitive bidding.

Other

    In the market for medical-grade polymers and enteral nutrition-delivery
systems, the Company competes primarily with large pharmaceutical,
medical-device, and chemical companies, many of which have substantially greater
financial, technical, and human resources than those of the Company. Competition
within these markets is intense, and is based primarily on price, efficacy, and
technological advances.



                                       10
<PAGE>
    (xii)   Environmental Protection Regulations

    The Company believes that compliance by the Company with federal, state, and
local environmental protection regulations will not have a material adverse
effect on its capital expenditures, earnings, or competitive position.

    (xiii)  Number of Employees

    As of January 2, 1999, the Company employed 2,045 people.

(d) Financial Information About Geographic Areas

    Financial information about geographic areas is summarized in Note 13 to
Consolidated Financial Statements in the Registrant's 1998 Annual Report to
Shareholders, which information is incorporated herein by
reference.

(e) Executive Officers of the Registrant

     Name                 Age  Present Title (Fiscal Year First
                               Became Executive Officer)
     -----------------------------------------------------------------

     John T. Keiser        63  President and Chief Executive Officer
                                 (1998)
     Victor L. Poirier     57  Senior Vice President (1983)
     Theo Melas-Kyriazi    39  Chief Financial Officer (1998)
     Paul F. Kelleher      56  Chief Accounting Officer (1985)

    Each executive officer serves until his successor is chosen or appointed and
qualified, or until earlier resignation, death, or removal. All executive
officers, except Messrs. Keiser and Melas-Kyriazi, have held comparable
positions for at least five years, either with the Company or with its parent
company, Thermo Electron. Mr. Keiser was appointed Senior Vice President of the
Company in 1994. At the same time, he was named President of Thermo Biomedical,
a newly created subsidiary of Thermo Electron. He was named President and Chief
Executive Officer of the Company in March and December 1998, respectively. From
1985 until 1994, he was President of the Eberline Instrument division of Thermo
Instrument Systems Inc., a majority-owned public subsidiary of Thermo Electron.
Mr. Melas-Kyriazi was appointed Chief Financial Officer of the Company and
Thermo Electron on January 1, 1999. He joined Thermo Electron in 1986 as
Assistant Treasurer, and became Treasurer in 1988. In 1994, he was named
President and Chief Executive Officer of ThermoSpectra Corporation, a public
subsidiary of Thermo Instrument. In 1998, he became Vice President of Corporate
Strategy for Thermo Electron. He remains a Vice President of Thermo Electron.
Messrs. Keiser, Melas-Kyriazi, and Kelleher are full-time employees of Thermo
Electron, and Mr. Poirier is a full-time employee of Thermo Cardiosystems, but
they devote such time to the affairs of the Company as the Company's needs
reasonably require.

Item 2.     Properties

    The Company believes that its facilities are in good condition and are
adequate to meet its current needs and that other suitable space is readily
available if any leases are not extended. The location and general character of
the Company's properties by industry segment as of January 2, 1999, are as
follows:

Quality Assurance and Security Products

    The Quality Assurance and Security Products segment operates from two
principal facilities: an 85,000-square foot office, research and development,
and manufacturing facility in Massachusetts occupied under a lease expiring in
2006, subject to one five-year renewal option at the election of the Company;
and a 115,000-square foot office and manufacturing facility in Massachusetts,
occupied under a lease expiring in 2005. The Company also leases approximately
10,000 square feet in Enschede, Holland, occupied under a lease expiring in
2000. In addition, the



                                       11
<PAGE>

Company leases approximately 20,400 square feet of office space throughout the
world for its sales and service operations, and owns approximately 14,300 square
feet of manufacturing, office, and storage facilities in Scotland.

Precision Weighing and Inspection Equipment

    The Precision Weighing and Inspection Equipment segment owns approximately
26,500 square feet of office, engineering, and production space in Canada and
the United Kingdom and leases approximately 324,500 square feet of office,
engineering, and production space principally in Minnesota, the United Kingdom,
Australia, and Germany under leases expiring at various dates through 2068.

Heart Assist and Blood Testing Devices

    The Company's Heart Assist and Blood Testing Devices segment owns
approximately 61,000 square feet of office, engineering, laboratory, and
production space in New Jersey and leases approximately 83,000 square feet of
office, engineering, laboratory, and production space in California,
Massachusetts, and New Jersey, under leases expiring at various dates through
2004.

Power Electronics and Test Equipment

    The Power Electronics and Test Equipment segment leases approximately
110,000 square feet of office, engineering, laboratory, and production space
principally in Massachusetts, Washington, California, the United Kingdom, and
the Netherlands, under leases expiring at various dates through 2010.
Approximately 40,400 square feet of office, engineering, laboratory, and
production space that the Company owns in Mount Kisco, New York, is currently
under agreement to be sold.

Other

    The Company also leases approximately 131,000 square feet of office,
engineering, laboratory, and production space in Massachusetts and Illinois,
under leases expiring at various dates through 2004.

Item 3.     Legal Proceedings

    Not applicable.

Item 4.     Submission of Matters to a Vote of Security Holders

    Not applicable.


                                       12
<PAGE>
                                  PART II
Item 5.     Market for Registrant's Common Equity and Related Stockholder
            Matters

    Information concerning the market and market price for the Registrant's
Common Stock, $.10 par value, and dividend policy are included under the
sections labeled "Common Stock Market Information" and "Dividend Policy" in the
Registrant's 1998 Annual Report to Shareholders
and is incorporated herein by reference.

Item 6.     Selected Financial Data

    Information concerning the Registrant's selected financial data is included
under the sections labeled "Selected Financial Information" and "Dividend
Policy" in the Registrant's 1998 Annual Report to Shareholders
and is incorporated herein by reference.

Item 7.     Management's Discussion and Analysis of Financial Condition and
            Results of Operations

    The information required under this item is included under the heading
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" in the Registrant's 1998 Annual Report to Shareholders and
is incorporated herein by reference.

Item 7A.    Quantitative and Qualitative Disclosures About Market Risk

    The information required under this item is included under the heading
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" in the Registrant's 1998 Annual Report to Shareholders and
is incorporated herein by reference.

Item 8.     Financial Statements and Supplementary Data

    The Registrant's Consolidated Financial Statements as of January 2, 1999,
are included in the Registrant's 1998 Annual Report to Shareholders and are
incorporated herein by reference.

Item 9.     Changes in and Disagreements with Public Accountants on Accounting
            and Financial Disclosure

    Not applicable.

                                       13
<PAGE>
                                  PART III
Item 10.    Directors and Executive Officers of the Registrant

    The information concerning directors required under this item is
incorporated herein by reference from the material contained under the caption
"Election of Directors" in the Registrant's definitive proxy statement to be
filed with the Securities and Exchange Commission pursuant to Regulation 14A,
not later than 120 days after the close of the fiscal year. The information
concerning delinquent filers pursuant to Item 405 of Regulation S-K is
incorporated herein by reference from the material contained under the heading
"Section 16(a) Beneficial Ownership Reporting Compliance" under the caption
"Stock Ownership" in the Registrant's definitive proxy statement to be filed
with the Securities and Exchange Commission pursuant to Regulation 14A, not
later than 120 days after the close of the fiscal year.

Item 11.    Executive Compensation

    The information required under this item is incorporated herein by reference
from the material contained under the caption "Executive Compensation" in the
Registrant's definitive proxy statement to be filed with the Securities and
Exchange Commission pursuant to Regulation 14A, not later than 120 days after
the close of the fiscal year.

Item 12.    Security Ownership of Certain Beneficial Owners and Management

    The information required under this item is incorporated herein by reference
from the material contained under the caption "Stock Ownership" in the
Registrant's definitive proxy statement to be filed with the Securities and
Exchange Commission pursuant to Regulation 14A, not later than 120 days after
the close of the fiscal year.

Item 13.    Certain Relationships and Related Transactions

    The information required under this item is incorporated herein by reference
from the material contained under the caption "Relationship with Affiliates" in
the Registrant's definitive proxy statement to be filed with the Securities and
Exchange Commission pursuant to Regulation 14A, not later than 120 days after
the close of the fiscal year.


                                       14
<PAGE>
                                  PART IV
Item 14.    Exhibits, Financial Statement Schedules, and Reports on Form 8-K

(a,d)       Financial Statements and Schedules.

    (1)The consolidated financial statements set forth in the list below are
       filed as part of this Report.

    (2)The consolidated financial statement schedule set forth in the list below
       is filed as part of this Report.

    (3)Exhibits filed herewith or incorporated herein by reference are set forth
       in Item 14(c) below.

    List of Financial Statements and Schedules Referenced in this Item 14

    Information incorporated by reference from Exhibit 13 filed herewith:

       Consolidated Statement of Income
       Consolidated Balance Sheet
       Consolidated Statement of Cash Flows
       Consolidated Statement of Comprehensive Income and Shareholders'
        Investment
       Notes to Consolidated Financial Statements
       Report of Independent Public Accountants

    Financial Statement Schedules filed herewith:

       Schedule II:  Valuation and Qualifying Accounts

    All other schedules are omitted because they are not applicable or not
    required, or because the required information is shown either in the
    financial statements or in the notes thereto.

(b)         Reports on Form 8-K

On  December 10, 1998, the Company filed a Current Report on Form 8-K dated
    December 10, 1998, the purpose of which was to provide an update to a
    proposed corporate reorganization by Thermo Electron, involving certain of
    Thermo Electron's subsidiaries, including the Company.

(c)         Exhibits

    See Exhibit Index on the page immediately preceding exhibits.


                                       15
<PAGE>
                                 SIGNATURES
    Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed by
the undersigned, thereunto duly authorized.

Date:  March 17, 1999               THERMEDICS INC.


                                    By: /s/ John T. Keiser
                                        John T. Keiser
                                        President and Chief Executive
Officer

    Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities indicated, as of March 17, 1999.

Signature                                 Title
---------                                 -----

By: /s/ John T. Keiser                    President, Chief Executive Officer, 
    John T. Keiser                        and Director

By: /s/ Theo Melas-Kyriazi                Chief Financial Officer
    Theo Melas-Kyriazi

By: /s/ Paul F. Kelleher                  Chief Accounting Officer
    Paul F. Kelleher

By: /s/ T. Anthony Brooks                 Director
    T. Anthony Brooks

By: /s/ Peter O. Crisp                    Director
    Peter O. Crisp

By: /s/ Paul F. Ferrari                   Director
    Paul F. Ferrari

By: /s/ George N. Hatsopoulos             Director
    George N. Hatsopoulos

By: /s/ John N. Hatsopoulos               Director
    John N. Hatsopoulos

By: /s/ John W. Wood Jr.                  Chairman of the Board and Director
    John W. Wood Jr.

By: /s/ Nicholas T. Zervas                Director
    Nicholas T. Zervas


                                       16
<PAGE>
                  Report of Independent Public Accountants
To the Shareholders and Board of Directors of Thermedics Inc.:

    We have audited, in accordance with generally accepted auditing standards,
the consolidated financial statements included in Thermedics Inc.'s Annual
Report to Shareholders incorporated by reference in this Form 10-K, and have
issued our report thereon dated February 11, 1999. Our audits were made for the
purpose of forming an opinion on those statements taken as a whole. The schedule
listed in Item 14 on page 15 is the responsibility of the Company's management
and is presented for purposes of complying with the Securities and Exchange
Commission's rules and is not part of the basic consolidated financial
statements. The schedule has been subjected to the auditing procedures applied
in the audits of the basic consolidated financial statements and, in our
opinion, fairly states in all material respects the consolidated financial data
required to be set forth therein in relation to the basic consolidated financial
statements taken as a whole.



                                               Arthur Andersen LLP



Boston, Massachusetts
February 11, 1999


                                       17
<PAGE>
SCHEDULE II

                                 THERMEDICS INC.
                        Valuation and Qualifying Accounts
                                 (In thousands)
<TABLE>
<CAPTION>
<S>                                 <C>         <C>         <C>         <C>         <C>         <C>


Description                                      Provision    Accounts    Accounts   Other (a)     Balance
                                    Balance at  Charged to   Recovered     Written                  at End
                                     Beginning     Expense                                         of Year
                                            of                                 Off
                                          Year
----------------------------------- ----------- ----------- ----------- ----------- ----------- -----------

Allowance for Doubtful Accounts

Year Ended January 2, 1999              $4,207      $1,002      $    -      $(1,614)    $  903      $4,498

Year Ended January 3, 1998              $4,903      $  815      $    -      $(1,406)    $ (105)     $4,207

Year Ended December 28, 1996            $4,244      $1,352      $  206      $(1,048)    $  149      $4,903



Description                                               Amount      Expenditures   Other (c)     Balance
                                              Balance at  Capitalized                               at End
                                               Beginning  as Cost of                               of Year
                                                 of Year  Acquisition
--------------------------------------------- ----------- ----------- ------------- ----------- -----------

Accrued Acquisition Reserves (b)

Year Ended January 2, 1999                        $  259      $1,309       $  (592)     $  (11)     $  965

Year Ended January 3, 1998                        $  903      $  299       $  (839)     $ (104)     $  259

Year Ended December 28, 1996                      $1,402      $  758       $(1,151)     $ (106)     $  903

(a) Includes allowance of businesses acquired and disposed of during the year as
    described in Note 3 to Consolidated Financial Statements in the Registrant's
    1998 Annual Report to Shareholders and the effect of foreign currency
    translation.
(b) The nature of the activity in this account is described in Note 3 to
    Consolidated Financial Statements in the Registrant's 1998 Annual Report to
    Shareholders.
(c) Represents reversal of accrued acquisition expenses and corresponding
    reduction of cost in excess of net assets of acquired companies resulting
    from finalization of restructuring plans and the effect of foreign currency
    translation.

</TABLE>


                                       18
<PAGE>

                               EXHIBIT INDEX
Exhibit
Number     Description of Exhibit

  2.1      Asset and Stock Purchase Agreement dated as of January 28, 1994,
           between Thermo Electron and Baker Hughes Incorporated (filed as
           Exhibit 2.1 to the Registrant's Current Report on Form 8-K relating
           to events occurring on March 16, 1994 [File No. 1-9567] and
           incorporated herein by reference).

  2.2      Assignment and Assumption Agreement dated March 16, 1994, among
           Thermo Electron, the Registrant, and Thermo Instrument Systems Inc.
           (filed as Exhibit 2.2 to the Registrant's Current Report on Form 8-K
           relating to events occurring on March 16, 1994 [File No. 1-9567] and
           incorporated herein by reference).

  2.3      Agreement and Plan of Merger dated as of November 29, 1995, by and
           among the Registrant, ATI Merger Corp., Analytical Technology, Inc.,
           and, for certain limited purposes, Thermo Instrument Systems Inc.
           (filed as Exhibit 2 to the Registrant's Current Report on Form 8-K
           relating to events occurring on November 29, 1995 [File No. 1-9567]
           and incorporated herein by reference).

  2.4      Asset and Share Purchase Agreement dated as of November 29, 1995, by
           and among Thermo Instrument Systems Inc., ATI Acquisition Corp.,
           Analytical Technology, Inc., and, for certain limited purposes, the
           Registrant (filed as Exhibit 10(a) to the Registrant's Current Report
           on Form 8-K relating to events occurring on November 29, 1995 [File
           No. 1-9567] and incorporated herein by reference).

  2.5      Asset Purchase Agreement dated as of January 25, 1996, among
           Thermedics Detection Limited, Moisture Systems Corporation, Moisture
           Systems Limited, and Anacon Corporation (filed as Exhibit 2.5 to the
           Registrant's Annual Report on Form 10-K for the fiscal year ended
           December 30, 1995 [File No. 1-9567] and incorporated herein by
           reference). Schedules to this Agreement have been omitted pursuant to
           Rule 601(b)(2) of Regulation S-K. The Registrant hereby undertakes to
           furnish supplementally a copy of any omitted schedule to the
           Commission upon request.

  2.6      Agreement and Plan of Reorganization among Thermo Cardiosystems Inc.,
           ITC Acquisition Corp., Thermo Electron Corporation, ITC Holdings
           Inc., and International Technidyne Corporation dated as of May 2,
           1997 (filed as Exhibit 2.1 to Thermo Cardiosystems' Quarterly Report
           on Form 10-Q for the quarter ended March 29, 1997 [File No. 1-10114]
           and incorporated herein by reference).

  3.1      Articles of Organization (filed as Exhibit 3(a) to the Registrant's
           Annual Report on Form 10-K for the fiscal year ended December 31,
           1988 [File No. 1-9567] and incorporated
           herein by reference).

  3.2      Amendment to Articles of Organization dated October 25, 1993 (filed
           as Exhibit 3(c) to the Registrant's Quarterly Report on Form 10-Q
           for the fiscal quarter ended October 2, 1993 [File No. 1-9567] and
           incorporated herein by reference).

  3.3      Amended and Restated Articles of Incorporation of the Registrant
           (filed as Exhibit 3(i) to the Registrant's Quarterly Report on Form
           10-Q for the fiscal quarter ended June 29, 1996 [File No. 1-9567] and
           incorporated herein by reference).

  3.4      Amended and Restated By-laws of the Registrant (filed as Exhibit 3(c)
           to the Registrant's Quarterly Report on Form 10-Q for the fiscal
           quarter ended March 28, 1992 [File No. 1-9567] and incorporated
           herein by reference).

  4.1      Fiscal Agency Agreement dated January 5, 1994, among Thermo
           Cardiosystems, Thermo Electron, and Chemical Bank (filed as Exhibit
           4.11 to Thermo Cardiosystems' Annual Report on Form 10-K for the
           fiscal year ended January 1, 1994 [File No. 1-10114] and incorporated
           herein by reference).



                                       19
<PAGE>

Exhibit
Number     Description of Exhibit

  4.2      Fiscal Agency Agreement dated November 19, 1993, among Thermo Voltek,
           Thermo Electron, and Chemical Bank (filed as Exhibit 4.3 to Thermo
           Voltek's Annual Report on Form 10-K for the fiscal year ended January
           1, 1994 [File No. 1-10574] and incorporated herein by reference).

  4.3      Fiscal Agency Agreement dated as of June 3, 1996, among Thermedics,
           Thermo Electron, and Chemical Bank, as fiscal agent (filed as Exhibit
           4 to the Registrant's Quarterly Report on Form 10-Q for the fiscal
           quarter ended June 29, 1996 [File No. 1-9567] and incorporated herein
           by reference).

  4.4      Guarantee Reimbursement Agreement dated February 7, 1994, among
           Thermo Cardiosystems, Thermo Voltek, the Registrant, and Thermo
           Electron (filed as Exhibit 4.4 to the Registrant's Annual Report on
           Form 10-K for the fiscal year ended January 1, 1994 [File No. 1-9567]
           and incorporated herein by reference).

  4.5      Fiscal Agency Agreement dated as of May 14, 1997, among Thermo
           Cardiosystems Inc., Thermo Electron Corporation, and Bankers Trust
           Company as fiscal agent relating to $70 million principal amount of 4
           3/4% Convertible Subordinated Debentures due 2004 (filed as Exhibit 4
           to Thermo Cardiosystems' Quarterly Report on Form 10-Q for the
           quarter ended June 28, 1997 [File No. 1-10114] and incorporated
           herein by reference).

           The Registrant hereby agrees, pursuant to Item 601(b)(4)(iii)(A) of
           Regulation S-K, to furnish to the Commission upon request, a copy of
           each other instrument with respect to other long-term debt of the
           Company or its subsidiaries.

 10.1      Amended and Restated Corporate Services Agreement between Thermo
           Electron and the Registrant dated as of January 3, 1993 (filed as
           Exhibit 10(a) to the Registrant's Annual Report on Form 10-K for the
           fiscal year ended January 2, 1993 [File No. 1-9567] and incorporated
           herein by reference).

 10.2      Lease dated November 1983 between WGO Limited Partnership, as Lessor
           and the Registrant, as Lessee (filed as Exhibit 10(l) to the
           Registrant's Registration Statement on Form S-1 [Reg. No. 2-96962]
           and incorporated herein by reference; amendments thereto filed as
           Exhibit 10(l) to the Registrant's Annual Report on Form 10-K for the
           fiscal year ended December 31, 1988 [File No. 1-9567] and
           incorporated herein by reference).

 10.3      Thermo Electron Corporate Charter as amended and restated effective
           January 3, 1993 (filed as Exhibit 10(h) to the Registrant's Annual
           Report on Form 10-K for the fiscal year ended January 2, 1993 [File
           No. 1-9567] and incorporated herein by reference).

 10.4      Lease dated August 25, 1978, between National Boulevard Bank of
           Chicago and Walpak Company (filed as Exhibit 10(p) to the
           Registrant's Annual Report on Form 10-K for the fiscal year ended
           December 31, 1988 [File No. 1-9567] and incorporated
           herein by reference).

 10.5      Exclusive Base Technology License Agreement between Thermo Electron
           and the Registrant dated January 8, 1988 (filed as Exhibit 10(q) to
           the Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
           ended April 2, 1988 [File No. 1-9567] and incorporated herein by
           reference).

 10.6      Research and Development Contract between Thermo Electron and the
           Registrant dated January 8, 1988 (filed as Exhibit 10(r) to the
           Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
           ended April 2, 1988 [File No. 1-9567] and incorporated herein by
           reference).


                                       20
<PAGE>
Exhibit
Number     Description of Exhibit

 10.7      Exclusive License and Marketing Agreement between Thermo Electron and
           the Registrant dated January 8, 1988 (filed as Exhibit 10(s) to the
           Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
           ended April 2, 1988 [File No. 1-9567] and incorporated herein by
           reference).

 10.8      Intellectual Property Cross-license Agreement between the Registrant
           and Thermo Cardiosystems (filed as Exhibit 10(i) to Thermo
           Cardiosystems' Registration Statement on Form S-1 [Reg. No.
           33-25144] and incorporated herein by reference).

 10.9      Amendment No. 1 dated March 29, 1991, to Exclusive License and
           Marketing Agreement between the Registrant and Thermo Electron (filed
           as Exhibit 10(r) to the Registrant's Quarterly Report on Form 10-Q
           for the fiscal quarter ended March 30, 1991 [File No. 1-9567] and
           incorporated herein by reference).

 10.10     Management Agreement by and between Thermo Electron and the
           Registrant dated November 15, 1991 (filed as Exhibit 10(t) to the
           Registrant's Annual Report on Form 10-K for the fiscal year ended
           December 28, 1991 [File No. 1-9567] and incorporated
           herein by reference).

 10.11     Agreement dated May 26, 1993, between Thermo Cardiosystems and The
           Polymer Technology Group, Incorporated (filed as Exhibit 10(nn) to
           the Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
           ended July 3, 1993 [File No. 1-9567] and incorporated herein by
           reference).

10.12      Amended and Restated Master Repurchase Agreement dated as of July 2,
           1996, between the Registrant and Thermo Electron (filed as Exhibit
           10.12 to the Registrant's Annual Report on Form 10-K for the fiscal
           year ended December 28, 1996 [File No. 1-9567] and incorporated
           herein by reference).

 10.13     $38,000,000 Promissory Note dated as of December 11, 1995, issued by
           the Registrant to Thermo Electron (filed as Exhibit 10(b) to the
           Registrant's Current Report on Form 8-K relating to events occurring
           on November 29, 1995 [File No. 1-9567] and incorporated herein by
           reference).

 10.14     $15,000,000 Promissory Note dated as of February 13, 1996,
           issued by the Company to Thermo Electron (filed as Exhibit 10
           to the Registrant's Quarterly Report on Form 10-Q for the
           fiscal quarter ended March 30, 1996 [File No. 1-9567] and
           incorporated herein by reference).

 10.15-17  Reserved.

 10.18     Incentive Stock Option Plan of the Registrant (filed as Exhibit
           10(d) to the Registrant's Registration Statement on Form S-1 [Reg.
           No. 33-84380] and incorporated herein by reference). (Maximum
           number of shares issuable in the aggregate under this plan and the
           Registrant's Nonqualified Stock Option Plan is 1,931,923 shares,
           after adjustment to reflect share increases approved in 1986 and
           1992, 5-for-4 stock split effected in January 1985, 4-for-3 stock
           split effected in September 1985, and 3-for-2 stock splits
           effected in October 1986 and November 1993.)

 10.19     Nonqualified Stock Option Plan of the Registrant (filed as Exhibit
           10(e) to the Registrant's Registration Statement on Form S-1 [Reg.
           No. 33-84380] and incorporated herein by reference). (Maximum number
           of shares issuable in the aggregate under this plan and the
           Registrant's Incentive Stock Option Plan is 1,931,923 shares, after
           adjustment to reflect share increases approved in 1986 and 1992,
           5-for-4 stock split effected in January 1985, 4-for-3 stock split
           effected in September 1985, and 3-for-2 stock splits effected in
           October 1986 and November 1993.)


                                       21
<PAGE>

Exhibit
Number     Description of Exhibit

 10.20     Equity Incentive Plan of the Registrant (filed as Appendix A to the
           Proxy Statement dated May 10, 1993, of the Registrant [File No.
           1-9567] and incorporated herein by reference). (Maximum number of
           shares issuable is 1,500,000 shares, after adjustment to reflect
           3-for-2 stock split effected in November 1993.)

 10.21     Thermedics Inc. - Thermedics Detection Inc. Nonqualified Stock Option
           Plan (filed as Exhibit 10.20 to Thermo Electron's Annual Report
           on Form 10-K for the fiscal year ended January 2, 1993 [File
           No. 1-8002] and incorporated herein by reference).

 10.22     Thermedics Inc. - Thermo Sentron Inc. Nonqualified Stock Option
           Plan (filed as Exhibit 10.51 to Thermo Cardiosystems' Annual
           Report on Form 10-K for the fiscal year ended December 30, 1995
           [File No. 1-10114] and incorporated herein by reference).

 10.23     Thermedics Inc. - Thermo Cardiosystems Inc. Nonqualified Stock
           Option Plan (filed as Exhibit 4(b) to Thermo Cardiosystems'
           Registration Statement on Form S-8 [Reg. No. 33-45282] and
           incorporated herein by reference).

 10.24     Thermedics Inc. - Thermo Voltek Corp. Nonqualified Stock Option
           Plan (filed as Exhibit 10.24 to the Registrant's Annual Report
           on Form 10-K for the fiscal year ended January 3, 1998 [File
           No. 1-9567] and incorporated herein by reference).

 10.25     Directors Stock Option Plan of the Registrant (filed as Exhibit 10.20
           to the Registrant's Annual Report on Form 10-K for the fiscal year
           ended December 31, 1994 [File No. 1-9567] and incorporated herein by
           reference).

 10.26     Deferred Compensation Plan for Directors of the Registrant
           (filed as Exhibit 10(g) to the Registrant's Registration
           Statement on Form S-1 [Reg. No. 33-96962] and incorporated
           herein by reference).

           In addition to the stock-based compensation plans of the Registrant,
           the executive officers of the Registrant may be granted awards under
           stock-based compensation plans of Thermo Electron for services
           rendered to the Registrant or to such affiliated corporations. The
           terms of such plans are substantially the same as those of the
           Registrant's Equity Incentive Plan.

 10.27     Restated Stock Holdings Assistance Plan and Form of Promissory Note
           (filed as Exhibit 10.27 to the Registrant's Annual Report on Form
           10-K for the fiscal year ended January 3, 1998 [File No. 1-9567] and
           incorporated herein by reference).

 10.28     Amended and Restated Master Guarantee Reimbursement and Loan
           Agreement, dated December 10, 1997, between Thermo Electron and the
           Registrant (filed as Exhibit 10.28 to the Registrant's Annual Report
           on Form 10-K for the fiscal year ended January 3, 1998 [File No.
           1-9567] and incorporated herein by reference).

 13        Annual Report to Shareholders for the year ended January 2, 1999
           (only those portions incorporated herein by reference).

 21        Subsidiaries of the Registrant.

 23        Consent of Arthur Andersen LLP.

 27        Financial Data Schedule.