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 163
of the coin. Remarks. The course of rays, or pencils of light,is divided into three kinds, viz. parallel, converging,and diverging rays. Rays are called parallel,when they would pass to in-finity at equal distances fromeach other, as n l o m.When rays of light issuefrom bodies at immense… … REFRACTED VISION. 161 rays of light on the earth ; but as the distance is soimmense, and the angle of divergency so infinitelysmall, the rays may be fairly considered as passingin the same parallelism. Converging rays are those which, in passing froma rare to a denser medium, are refracted or bent…
Physics
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![An illustration from Examen dv livre des Recreations mathematiqves, & de ses problemes en geometrie mechanique, optique & catoptrique [du J. Leurechon] Où sont aussi discutées & restabiles plusieurs experiences physiques y proposées (1639)](https://img.insideoutlibrary.com/img/200/ia-examendvlivredes00mydo-81-16.webp)