ive to use this “ Mural circle,” but Pond had the advantage of it; and he subsequently had another one made like it, using the two together. Pond also had a new Transit made by Troughton, of 5-inch aperture, which was a masterpiece; and with these means he pushed observing accuracy to a point that… … 1. Halley’s Transit (1721-1749). 4. Mural Quadrant (1725-1812). 2. Bradley’s Transit (1750-1816). 5. Troughton’s Transit (1816-1850.) 3. Bradley’s Zenith Sector. 6. Mural Circle (1812-1850). about J inch to the foot: the cut also shows the form of Bradley’s famous Zenith Sector, with which he…
Astronomy · Greenwich Observatory · Longitude
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