Grimthorpe, Edmund Beckett, Baron, 1816-1905 · New York : G.P. Putnam · leaf 44
Eccentricit/y and ElUpticity. 39 of paper, leaving the string quite loose between them ; put a pencil in to stretch the string out, and run it along, always keeping the string tight: then the pencil T/ill describe an ellipse. Here is a figure of an ellipse with the circle contain- ing it. SPII is… … the string or SP-I-HP, or twice SB. BCF is the axis ininor. The nearer together the foci are, the more the ellipse apjjroaches a circle, or the less eccentric it is : the proportion of CS to CA (not OS alone) is called the eccentricity, which is there- fore expressed by a fraction, either a vulgar…
Astronomy
Internet Archive · Cornell University Library · Public domain (published before 1931). Free to use for anything.
