Scope and Contents

The National Company (NATCO) Atomic Clocks Records, 1955-1968, documents the development of the first commercial atomic clocks. Materials were generated by the National Company, Inc. (NATCO) of Malden, Massachusetts which produced the clocks under contract for military branches of the U.S. government and also marketed them on a retail basis. The collection consists of blueprints, technical drawings and schematics, technical and research reports, instruction manuals, photographs, marketing materials, and a stock offering prospectus for NATCO. If one blueprint, drawing or parts list had two or more models listed, it is included under the first model cited.

Series 1, National Company, Inc., (NATCO), 1957-1959, consists of a stock offering prospectus, 1959, which describes the organization of NATCO, its executives and Board of Directors, financial condition, and products. Located in this series is a bound volume of photographs which accompanied NATCO's contract bids. This volume contains photographs of a state-of-the-art machine shop and electronics laboratory of the late 1950s and early 1960s. A blueprint for a radio receiver— the product on which NATCO had built its reputation—is here.

Series 2, Atomichrons, 1955-1968, contains blueprints, original technical drawings and schematics, instruction manuals for setup and operation, technical and research reports, photographs and marketing materials arranged by Atomichron model from the National Atomic Frequency System (NAFS) prototype through the NC3701 and NC3702. The NC1001, the first commercial atomic clock, is fully documented. Technical Memoranda and proposals (TM-) related to particular models have been included with them. Other Technical Memoranda and proposals are in Series 3, Components, 1955-1957, and Series 5, Technical Memoranda and Reports, 1956-1957.

Series 3, Components, 1955-1967, contains materials related to the development of NATCo's Cesium Beam Tube and other parts of the Atomichrons. It includes Technical Memoranda (TM-), blueprints and original drawings, original notes and computations, parts lists, and photographs. Also included in this series is material related to the Production Engineering Measure (PEM), 1962-1967. This was a piece of equipment designed and built by NATCO to measure the accuracy of each Cesium Beam Tube as it was produced.

Series 4, Collision Avoidance System, 1962-1967, consists of material related to James J. Bagnall's patented Collision Avoidance System, using the Cesium Beam Frequency Standard. It includes his research report, the patent assigned to NATCO, and proposals and reports from NATCO representatives to Air Transportation Association conferences and meetings for 1967.

Series 5, Technical Memoranda and Reports, 1956-1967, consists of bound and numbered (TM-) technical memoranda. These are research reports and proposals for future research or products. Other technical memoranda are in Series 2, Atomichrons and Series 3, Components, 1955-1967.

Series 6, Reprints from Massachusetts Institute of Technology (MIT), 1953-1955, contains a bound volume of reprinted or photocopied papers which document research developments in Cesium Beam Frequency Standards at the time NATCO was establishing itself as a commercial producer.

Arrangement

The collection is arranged into six series.

Subseries 2.1, National Atomic Frequency System (NAF), 1956

Subseries 2.2, NC1001, 1955-circa 1959

Subseries 2.3, NC1001, Polaris, 1956-1958

Subseries 2.4, NC2001, Militarized, 1956-1961

Subseries 2.5, NC3001, Airborne, 1956-1961

Subseries 2.6, NC1200, 1959

Subseries 2.7, Missileborne Atomichron, 1959-1960

Subseries 2,8, NC1501, 1958-1964

Subseries 2.9, NC1601, Economy, 1958-1964

Subseries 2.10, Tactical Frequency Standard Drawings, 1959

Subseries 2.11, Tri-Service CBFS, circa 1965

Subseries 2.12, NC3501, circa 1965, 1967

Subseries 2.13, NC3601, Aerospace, circa 1965

Subseries 2.14, NC3701, Commercial, 1964-1968

Biographical / Historical

An atomic clock is a cesium-based frequency standard. It operates by exposing cesium atoms to microwaves at one end of their resonant frequencies and then counting their corresponding cycles as a measure of time. In 1955, Louis Essen of Britain's National Physical Laboratory and William Markowitz of the U.S. Naval Observatory collaborated to produce the first measurement of what is now called the atomic second. In 1967, the 13th general Conference of Weights and Measures formally redefined the atomic second as 9,192,631,770. The atomic second became the internationally accepted unit of time. Atomic clocks are the most accurate of all clocks. The first clock in 1949 was based on the microwave resonances of the ammonia molecule. It was patented by Harold Lyons and Benjamin F. Husten. The first commercial atomic clocks were developed at the Massachusetts Institute of Technology (MIT) Research Laboratory of Electronics under J.R. Zacharias, a protégé of I.I. Rabi's, circa 1955-1956 and were manufactured by the National Company, Inc. (NATCO) of Malden, Massachussets. NATCO, founded in 1914, was a well-respected company known for producing specialized electronic equipment in short runs. Prototype clocks bore the working name National Atomic Frequency Standard (NAFS). When the first commercial product was unveiled on October 3, 1956, it bore the trade name "Atomichron" and the model number NC-1001. Between 1956 and 1960, fifty Atomichrons were made and sold to military agencies, government agencies, and universities. Nine other models followed with refinements in size, portability and accuracy. The most radical design departure began with the NC3001 when the beam tube was placed in the horizontal position. Prices ranged from $10,000 to $50,000.

Patents covering NATCO's frequency standards include: 2,960,663, 2,972,115, 2,991,389, 3,258,713, 3,305,290. In 1965, James J. Bagnall was assigned patent 3,167,772 for a Collision Avoidance System to NATCO. It never reached production.

Although supported by research contracts by all three military branches, especially the Army Signal Corps, NATCO failed to achieve a lasting profitability. It was liquidated, and its patents were acquired by Frequency Electronics in 1969.

1. PEM Drawing C43767, 1967, PEM Drawings (C38037-C43767), 1964-1967, Series 3, Components, 1955-1967, Atomic Clock Collection, Archives Center, Smithsonian Institution National Museum of American History.

2. Forman, Paul. "Atomichron: The Atomic Clock from Concept to Commercial Product," in Proceedings of the IEEE, vol. 73, p. 1181-1204, 1985.

Related Materials

Industry on Parade (NMAH.AC.0507)

Reel #247, Making atomic clocks. National COmpany, Incorporated, Mauldin, Massachusetts.

Artifacts related to this collection are located in the Division of Work and Industry.

Materials related to MIT staff and departments who were involved in NATCO's Atomic Clock projects also can be found in the Historical Collections at the MIT Museum (http://web.mit.edu/museum/) and in the Institute Archives and Special Collections (http://libraries.mit.edu/archives/) of the MIT Libraries in Cambridge, Mass.