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 alt-azimuth instrument has ...

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 ...

II. AN important objection was made to me some years ago by Capt. Evans against the use of quadrantal correctors in the Navy, that they would prevent the taking of bearings by the prismatic azimuth ...

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 ...