Quinby on the Blowing Machinery of a Furnace. 129 
pipe. Hence for the volume discharged under the pressure 
p, and through an airpipe whose diameter is d, we havé 
113.04 ypxd? cubic feet per oe But M is also equal 
to the volume discharged per minu 
Therefore M=1 . = vpxd? (} 
When = 
ees ae 04x d?)" (il) 
ee (II) 
(113.04 x yp) 
Next, to get the velocity with which the ‘cxseel will move, 
we have D? : d? : : 20726x yp: os od SA - Andthis 
quantity divided by twice the length of - stroke, will give 
the number of strokes per minute. 
Hence N= — nee = (IV) 
Whence d=, ¥ eee ssl) 
2 2 
p= Oe (Vil) 
a VEX d? (VIN) 
And, now, to obtain the momentum of the piston,* we have 
——_—- 5 xd" x D? x .7854 x p=16278.2 x /px d? xp; 
ibs. raised one foot high _ min 
We must now change the a a of this momentum 
into that of cubic feet of water, raised one foot high per min- 
ute. To do this, aR RE Se the num- 
ber of Ibs. that are equal to one cubic foot of 
siecs ae XP _ 960.45 x Spaahee 
o Searain al i deo in cubie feet of water, raised one 
ot high per mi 
* By momen { the piston, is meant the product of the whole pressure 
and x space, in feet, through which the piston moves in one minute. 
VOL. XII,—No. 1. 37 
