ObfervationscfDr Papin, Fellow of tk Koyzl So- 
ciety , on a French Paper concerning a Perpe- 
tual Motion. 
THE Paper printed in French and containing a 
contrivance for a perpetual motion, being fet 
down in fuch a manner, that can hardly beunderftood 
but by thofe that are much acquainted with fuch defcrip- 
tions: I have endeavour d to explain it as follow s. 
LetZ)£F Fig. 9. be a pair of bellow's 4d^inches 
long, that may be open d by removing the part F from 
E: let them be exadly fliut every where but at the aper- 
ture jEj and let a pipe E G, 20 or 22 inches long, be fod- 
dered tothefay'd aperture £, having its other end in a 
Veffel G, full of Mercury , and placed hear the middle of 
the bellow's. 
-^, Is an axis for the bellow's to turn upon. 
j5, A counterpoile fattened to the lower end of the 
bellows, 
r, A weight with a clafp to keep the bell©w's upright. 
Now if Y>^e fuppofe the bellow's open'd only to \ or \ 
ftanding iipwright as Fig. ^th. aud fuUof Mercury, ic 
is plain that the faj'd Mercury being 40 inches high,muft 
fall, as i n the Torricellian experiment, to the heigth of a- 
bout 27 inches, and confequently the bellow's muft open 
towards f and leave a vacuity there: this vacuity muft 
be fill'd with the Mercury afcending from G through 
the Pipe G E, the layd Pipe being but 22 inches long : by 
this means the bellow's rauft be opened more and more 
till the Mercury continuing to afcend make s the upper 
part otthe bellow's fo heavy, that the lower part muft 
get loofe from the clafp C, and the bellow's fliould turn 
quite upfide downs but the VefTel G being fet in a conve- 
nient place keeps them horizontall as Fig. 10, and the 
part 
