Philosophical instructor, or, Webster's elements of natural philosophy : subdivided into principles and illustrations ; intended for academies, medical schools, and the popular class-room (1824)
Eaton, Amos, 1776-1842, Webster, John, fl. 1804-1824 · Albany : Printed by Websters and Skinners ... · leaf 166
e number of straightlines. Suppose e f two of thosestraight lines which formpart of the convex surfaceof a sphere, and that therays a f, be, fall parallelon the points e and r, thenit is evident, that as theselines are reflected in equalangles from the oblique linesverge, and lose their parallel…
Physics
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