Mechanical Theory of Heat to the Steam Engine. 35 
fied formula corresponds with sufficient accuracy to the more 
strict mode of calculation before signified. 
| i | - 0, |) a ee ee 2 oe 
r ace, to (52), 607-0 5716 53862 | 5008 | 465°4 | 
r acc. to Regnault, | 6065 571°6 5365 500°7 4643 
50. In order to be able to distinguish in their action the two 
different kinds of expansion to which the two last of equations 
XVII refer, it appears to me advantageous to consider, in the first 
ae a steam engine such that only one of them occurs in it. 
e will therefore begin with a machine which works without 
expansion. 
In this case we must put for the quantity e, which signifies the 
ratio of the volumes before and after expansion, the value 1, and 
at the same time make 7,=T7',, whereby equations XVII assume 
4 simpler form. 
The last of these equations becomes identical and therefore 
disappears. Furthermore, many terms of the first equation 
which only differ from the corresponding terms of the second in 
this, that the first contain 7’; and the others 7',, now become 
equal to them, and may therefore be eliminated. Hence we ob- 
4 iy introducing at the same time, the above-mentioned quan- 
y *, 
ue V(1—£)(Po-Po)-+9 (Ps —Po) 
(xvi) 4 (V-ic) 7, 9,= 4 ae =a) 
+e y (2a To) 4 pg -ps) +lo(p,—pz)- oe 
oO 
The first of these two equations is exactly the same as that 
which we obtain according to Pambour’s theory, if we put in 
(x11) e=1 and introduce the volume V in place of the pees 
e difference exists thus only in the second equation, W 
has taken the place of the simple relation between volume and 
pressure assumed by Pambour. in ee ‘seateia 
1. Let us assume the quantity e occurring in these equations, 
Which represents the injurious: as a fraction of the whole 
Space which becomes free for the steam, as equal to 0°05. The 
quantity of liquid which the steam carries with it, on its entrance 
into the cylinder, is different in different machines. Pambour 
ye that it amounts on the average in guste ~ A 
_ Statio ste ines however, to much less, perhaps to 0: 
of the whats nies Sh f inder. We will use 
of it which is in the form of steam is as 1 to 0-95. Furthermore, 
let the pressure in the boiler be assumed to be 5 atmospheres, 
