134 woolf's rotatory apparatus. 



farther Remarks on Mr, Woolf's Rotatoria Apparatus, 



^* w^ir"*^"""' ^ ^ ^^^^^" ^^ ^^^^^'^ the efTed of Mr. WoolPs contrivancq 

 tory apparatus/ {-^f^'- 1* ^^^^^ XI. Vol. VI. November .1^03.) more intelli- 

 gilple to my readers in general, I ihall here explain the fame 

 in a popular way. 



I will fuppofe, by way of fimplifying the fubjecl, that the 

 rod B is fo long as to act always nearly in the perpendicular, 

 and that the adion upon the fmall wheel is alfo in ithe fame 

 diredion, namely, conftantly that of gravity. The en- 

 graver has omitted to continue the rod of the pifton fup- 

 pofed to Work in the barrel G, and the proof canie too late 

 for it to be altered in time. The effedl at the pin F in the 

 little wheel, is precifely the fame as if a weight was conti- 

 nually hanging there. 

 Effeftofthe 1. In the pofition here (liewn, the power of the engine 



^^\oh Tn diffc- ^^^^ "^^ ^^ ^^ ^^^* ^"*^ ^^^^ weight at F has its full operation. 



^eqt pofitions. —2. When C has moved through half the quarter circle to 



the right hand, F will have arrived at the loweft point; 



confequently the poWer of the engine will aft by a lever 



eiqukl to the line of 45^, or feven-tenths of the radms: oi* 



feven-tenths of the full power of the engine will then a6l 



bn the great wheel, and the weight at F will no't a6l at all : 



—3. When C has moved through an entire quadrant, the 



power of the engine will be the greatefl poflible on the 



J^reat wheel, but at the fame time the weight will have 



arrived at the horizontal line beneath E, and will oppofe the 



former action. The motive force will therefore be equal 



to the excefs of the power of the engine beyorid the weight. 



4. When C has> moved through another half quadrant^ the 



action oh the great wheel will be equal to feveh«tenths, as 



i\\ No. 2. and the weight, having arrived at the highefl 



^ point will not ad at all. 5. When C has moved through 



half a circle, and is at the lower flation in the great wheel 



the engine will not ad, and the weight having arrived again 



at F. will have its full operation as in No. 1. 



four ' ^y P"^"^"^^g *^^^ fimple method of examination, we fee 



positions n .that 1. there are four pofitions in which the arm C tlanding 



which the coun- ^j. ^^ inclination of 45° to the horizon, and the arm F per- 



aocffe'l/ " p^jidicular to thefamelthe regulating weight cau' have no 



effe^, 



