The altitude and azimuth instruments made by Edward Troughton in London from the 1790s were remarkably stable and accurate, and Troughton & Simms continued this tradition. Indeed, Frederick W. Simms ...

IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This instrument came from the John C.

Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www ...

Three simulated satellite constellations, one per column. Starlink Gen1 is 4,408 satellites, Starlink Gen2 is 29,988 satellites, and OneWeb is 6,372 satellites, for a grand total of 40,768. The top ...