C483) 
He propofes the alternstcly turning a fmali Surface 
of Water into Vapour, by Fire applied to the bot- 
tom of the Cylinder that contains it, which Va- 
pour forces up the Plug in the Cylinder to a con- 
fiderable height, and which (as the Vapour conden- 
fes, as the Water cools when taken from the Fire) 
defcends again by the Airs Preffure, and is applied to 
raife the Water out of the Mine* 
V. The fifth concerns^a Difpute between Mr. 
minique GulielminiiZn^ Mr. F^/i»,concerning Running 
Waters, the Deciflion of which he refers to Mon- 
fieur Chriflkn Hngens ^ and is too long to be here 
inferted, 
VL The fixth is ah Abridgment of a Difpute be* 
tween himfclf and the fame Perfon,concerning the true 
Eftimate of Powers or Moving Forces. 
VIL The feventh treats of Inftruments to conferve 
Flame under Water , againft the Objedlions of 
Mr. Scarlet ; a Defcription whereof was Pub» 
liflied in the AHa EruJit. Anna 1689. p. 485^ 
Mr. Scarlet's Objedions thereto , were Pub» 
lifted in the (ame Afta^ Anno 1690. p> 5-31. to 
which our Author here Replies, for which t refer 
to the Treatife it felf, being of no great length» 
He ends with the Defcription of a Plunging-boat ^ . 
or Para ffepipide Vcid made of Tin, 5^ Foot high, 
5^l6ng, and broad, flrengthened with Crofs* 
Bars of Iron 5 which Veflel , by means of a Pump 
(which has Communication with the External Air 
above the Water) is to be continually fuppUed with 
freih Aif, by drawing down the Sucker of the 
Pump. 
