366 R. Clausius on the Application of the 
D 
engineer has opened the valve in the steam He and upon the 
velocity with which the machine moves. This difference may 
vary between wide limits by changing these conditions. The 
of the influx, at the moment of cutting off from the boiler. 
Though I do not consider it advantageous to introduce directly 
into the general formulas such an assumption, which is made 
only for the sake of numerical calculation in the absence of more 
a data, yet I must here follow his process in setting forth 
1s theor een 
ry. , 
Pambour determines the pressure which takes place in the 
cylinder at the moment of the cut-off by means of the relation 
established by him between volume and pressure, inasmuch as 
he thereby supposes that the quantity of steam passing into the 
cylinder, during the unit of time and consequently also, during 
one stroke of the piston, is known by special observations. We 
will as before denote by M the whole mass which enters the eyl- 
inder during a stroke of the piston, and that portion of it which 
is in the form of steam by m. As this mass, of which Pambour 
only considers the portion which is in the form of steam, fills the 
space ev’ at the moment of the cut-off, we have, if we denote the 
pressure at this moment by p, according to equation, (29) 
whence we have 
cabs 
(30.) a= ‘ 
