IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. The 5071A Cesium Primary Frequency ...
This instrument—made by Frequency and Time Systems Inc. (FTS), Danvers, Mass.—dates from the “concept validation phase” of the Global Positioning System (GPS) program between 1974 and 1978. It is ...
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