( 47 ) 
into two equal Parts, one half employed in fucking, 
and the other in blowing ; therefore the Half of 
145-. 88i Feet, which is 71.941 Feet, will reprefenc 
t he Height of a Column of Air, that would occafion 
the fame PrefTure with which the centrifugal Force 
and the circular Motion ad in this Machine ; and 
a Column of this Height producing a Velocity of 
68. fs Feet per Second. This Number will expreft 
the Velocity with which the Air is fucked into the 
Wheel •, and the fame Number will alfo exprefs the 
Velocity of the Air out of the Blower, proceeding 
from the centrifugal Force, and the circular Velocity 
of the outer Circle, which is the real Velocity of 
the Stream of Air out of the Blower of this Ma- 
chine, viz. 68. 53 Feet per Second, which is at the 
Rate of a Mile in about 77 Seconds, or about 
7 Miles in 9 Minutes. 
Ill.T^ellfeso/ the foregoirigMach'me^communicated 
in a Letter to Cromwell Mortimer, A/. ©., 
S. Seer. Feb. 13, 1 7 3 i. from the fame . 
SIR, 
A ccording to my Promife I fend you a further- 
Account of my centrifugal Wheel, which is 
now fix’d in a Room above the Houle of Commons,, 
to draw away the hot Steam arifing from the Candles, 
and the Breath of the Company in the Houfe, when, 
it is very full, in warm Weather; as alfo afterwards 
