[I24l] 
part F engageth there in another Clafp then the Mer- 
cury By its weight runs out from the bellows into the 
Veffei G through the Pipe EG, and the bellow's muft 
fhut clofer and clofer untill the part comes to be fo 
light, that the coanterpoife i?is able to make the "part F 
get loofe from the clafp Ci then the bellow's come to be 
upright again as Fig. 9th i the Mercury left in them fall s 
again to the heigth of 27 inches, andconfequently all 
the other effeds will follow as we have already feen, and 
the motion will continue for ever. Thus much the 
French Author. 
Upon this it is to be obferved,that the bellow's can ne- 
ver be opened by the internal preflure, unlefs the fayd 
prefTure be ftronger then the externall • now in this 
cafe the weight of the^^;?2(?/^^er^doth freely prefs up- 
the outward part of the bellow's, but it cannot come at 
the inward part but through the Pipe GE, which con- 
taining 22 perpendicular inches of Mercury, doth coun- 
terpoife fo much of the weight of the Atmosphere, fo that 
this being fuppofed to be 27 inches of Mercury, it can- 
not prefs the inward part of the bellow's but with a 
weight equivalent to 5 perpendicular inches of Mercu- 
ry. From this we may conclude, that the preiTure of the 
Atmoj^here being weakned within the bellow's,more then 
itcanbe helpt by the Mercury contain d in the fame, 
as may eafily be computed the fayd bellow's {landing 
upright as Fig. 9th 5 muft rather fhut then open. Thus^ 
without loofing any labour and charges in trying,people 
may be fare that the thing can never do. 
/ 
Qjq q 2 Edvardus 
