Herschel, John F. W. (John Frederick William), Sir, 1792-1871 · London : Longman, Rees Orme · leaf 30
explained), this would be atolerably good method of ascertaining it. Suppose Aand B to be two eminences, whose perpendicular heightsA a and Bb (which, for simplicity, we will suppose to beexactly equal) are known, as well as their exact hori-zontal interval a D 5, by measurement; then it is… … c know D b, the length of the arch of the circle between1) and by—viz. half the measured interval, and h B, theexcess of its secant above its radius —which is the heightcf \it—(]ata which, by the solution of an easy geometricalproblem, enable us to find the length of the radius D C.If, as is really…
Astronomy
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