A text book of geometrical drawing : abridged from the octavo edition : for the use of schools in which the definitions and rules of geometry are familiarly explained, the practical problems are arranged from the most simple to the more complex, and in their description technicalities are avoided as much as possible : with an introduction to isometrical drawing : and an essay on linear perspective and shadows ... (1849)
K. E perpen-dicular to /. K, cutting J. H extended in E. Thentake the distance H. E and set it off from / to F, thenF is the focus. 2nd. At any convenient distance above J, fasten aruler A. B^ parallel, to the base of the parabola C D. 3rd. Place a square S^ with one side against theedge of the… … Fuj.Z. ^r I ^ ^-^. 3 4-3?.! w=^m ^-^—=- =—- ^-^^-^=--^---_-.- _- __-_- -_^ .- , s .] r Fuj.S. \ H 5 1 1 3 F 3 2 1 //^ 3 . \ \ / /y/ 1 / / 2 M \/f/ \ ^ n / 1 \ ,\\\ /// \\ r 1 Vl^-Mui^^ ninuuiSj. PLATE XXI. 69 around it, and bring it down to JV, the end of thesquare, and fasten it there. 5th. With…
