Be il ila aia ee ees ees 
Mechanical Theory of Heat to the Steam Engine. 29 
which contain # as a factor are, in an event, very insignificant, 
we may substitute without hesitation also for « the same value 
which is found for «, that is, for the purpose of numerical caleu- 
lation, we may drop the assumption made for the sake of gene- 
rality, that the mass which was originally in the injurious space 
was partly fluid and partly vapor, and consider the mass in ques- 
tion as wholly in the form of vapor. 
The substitution just signified may be effected in the general 
equations (XIV) as well as in the simplified equations (xv). As 
the substitution however presents no difficulties, we will here 
confine ourselves to the last, in order to obtain the equations at 
once in a form which is suited to numerical computation. 
fter this change they read as follows: 
mm. pa T.-C T wes 
W'= at —(v'—-Mo)( 7 9,—P3+-Py) +80! Bad ei 
0 
+P2Po) 
0 
pores —P2) 
t , ev'\c 
44. Tn order to refer these equations, which determine the work 
of one stroke or of the quantity of steam M,, finally to the unit of 
r m,r,+Me(T,-T.),__,f?o-(T2-T 4) 
(xvi) (¢0'-Mo) 7, g.—= at a i al ben' ("2 a 0 
aoe v 
3 m m, my 
The equations now become 
a r,—¢(T,-T,) 
wantatl Tits) -(V-10)(7,95-Ps+Po)+* prot 
‘ a ass 
(xvn); (eV-Io) 7, eciiee of 7s), v(t ae ot py, -Po) 
+1o(p,-p2) 
: eV\e se 
(V—10)9,=(eV—l0)9,+(I+ aay log T,” 
45. The applicati uations to the calculation of the 
work ma é poe th tied manner. We determine the 
volume ; which belongs to the unit of weight of steam, by 
Means of the evaporating power supposed to be known, and of 
the rate of motion ohice the machine thereby assumes. With 
the help of this value, we calculate in the first place from the 
