$02 Agi. - uS. hsi OwwRmea-uret & 
$62. E b ede Acc of — 
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rel When the communicatio: is'opened by chi eter te 
om. ‘This pifton; therefore, will defcend as eafy as any Other 3! 
sii má Norm ‘hot impede the rarefaction; fince itis of no 
fequence, as to this, whether it open or riot. "By this cons 
éxsdius, othe valves, which Mr. Smeaton only made" to open 
with more.eafe, are rendered unneceflary in rarefyingothe air « 
and.that at. tlie bottom. of  the-barrel, which is thé moft diffi 
cult to-be made and kept in OP han ntirely--removed ^ that 
perse tts only o nece m : refying othe 
siib as wWisdev ned eàr: ogigi ote xq i9 
Butas ina fingle. bartdié pinay dbi EDA "Pw 
there is no valve:àt- the bottom to: prevent the air, which fol- 
lows up the pifton. in'its. afcent, from returning into the fe- 
ceiver in its defcent; a sieves would ba produceds: which 
aight rove deteiinadtahin foie isperiusinte; this -pusip 246 
made MTRS theair at every firoke: of 
the wineh.: In this contradtion, jte sapigi: of the two bar- 
zels, taken: together, below the piftons, desivo adea dw 
while 
Lain WERL dia gage ilL h en E ES 63 2 lasiin 
T m “or 5 TOO ND gs es ee 
takant G ee et a D 41 pix eee P qi mrs are art 
#3 1:3 V4. VV 4: eae 
Sn aay C AEN VAL SELES 2 
“Having thus fetafide the : valves, which in Leiadasene pré 
vented. anres qi MR Amm above the pifton; 
tween-the. piíton.-and.- the: top-plate, which would allow riai 
of the airo :expand. itfelfsinto the barrel from the receiver. 
But to fhow in what manner ] have attempted this, it will be 
means 
