( 17 ) 
, cificaJly lighter. And that this Steam is not made 
of the Air extricated out of the Water is plain, 
becaufe it is condens’d again into Water' by a .Jet 
if r fhe injeaed Water 
muft be discharged at- every Stroke, otherwife the 
Engine will not work well. There is alfo another 
Experiment to confirm this. 
ExPERIilENT. 
r ® of ^ater, which' 
imift be fet upon the Fire to boil. In this VelTel 
mull be fufpended the glafs Bell E, made heaw 
wough to fink in Water ; but put in, in fuc^a 
Manner that it be filled with Water when upnaht 
without any Bubbles of Air at its Crown within, fhe’ 
Crovvn being all under Water, As the Water boils 
tlie Bell will by Degrees be emptied of its Water’ 
being prefsM down by the Steam which rifes aboTe 
App«rTce'“of^I 
nf “‘I' 7 “'"•‘I » 
till only the Mouth remains under Water ; then Ts 
the Steam condenles by the cold Air nn rj 
of .W Bdl, .he ,t' M S 
F qtme to the Top without any Bubble above it 
which Ihews that the Steam which kept our the 
'Water was not Air. ^ 
N. B Tiu Experiment fucceeds bed when th^ 
JVater has been firfl pur^d of Jir u 
We know by feveral Experiments made on the 
Fire-Engine (in Captain Savery^ Way, where the 
^ Steam 
