Proportion Comp aft* p ? * 
§ 7. It will follow from hence, that thefe two movers, 
which we will fuppofe wheel and pinion, mull: recipro- 
cally raife the 30° required; but if you increafe one of 
thefe fo as to make a revolution more than the other, 
which is fixed at 1 2 teeth, and at one line diameter, this 
laft will indeed have 24 teeth; but inftead of two lines 
of diameter it will have only 23 and T '-th relatively 
to that of the pinion ; or if we give it exa&ly the double 
diameter, it will have 25 teeth inftead of 24; confe- 
quently upon three revolutions, or 36 teeth, one muft 
lubtradt from the wheel 2 and -^th of a line, and fo on 
as far as 1 2 or rather 1 x effective revolutions (for the firft, 
being fuppofed to be in equilibrio with its pinioxx, ought 
pinion of 12 which produces the fum of the 8th part of a tooth upon the 
wheel let its number be what it will. 
not 
§-7. II fuif-dela que ces deux mobiles que nous fuppoferons roue et pignon 
doivent lever reciproquement les 30° requis; mais fi 1’on augmente l’un de ces 
mobiles cFune revolution de l’autre qui ell fixee a 12 dents et une ligne de dia* 
metre, ce dernier aura bien 24 dents, mais au lieu'de deux lignes de diametre il 
n’aura que relativement a celuidu pignon, ou bien fi on luidonne exadtement 
le double en diametre il aura 25 dents au lieu de 24, parconfequent fur trois 
revolutions foit 36 dents, il en faudra retrancher de la roue J de ligne, ainfi de 
fuite jufqu’a 12 ou bien 11 revolutions effectives) parce que la premiere etant 
dent fur la roue de tel nombre qu’elle foit; neantmoins pour rendre les Judes rapports d’autant 
plus complets, j’ai fait entrer tout d’un terns cette petite compenfation en faveur du mobile qui 
mene dans les dimienfions de mon compas en queftion, pour tons les nombres et grandeurs des 
roues et pignons quelconques, &c. 
6 C 2 
cenfee 
