432 Prof. Clausius on the Application of the Mechanical 



1 : 0*95, Further, let the pressure in the boiler be five atmo- 

 spheres, to which the temperature 152°*22 belongs, and let us 

 suppose that the machine has no condenser, or, in other words, 

 let it have a condenser with the pressure of one atmosphere. 

 The mean reaction in the cylinder is accordingly greater than 

 one atmosphere. As before mentioned, the difference in loco- 

 motives may be considerable, but in stationary engines it is 

 smaller. With respect to stationary engines, Pambour has 

 altogether neglected this difference ; and as our only object at 

 present is to compare the new formulse with those of Pambour, 

 we will also disregard the difference, and let jt?o=l atmosphere. 

 In this example, therefore, the following values will have to 

 be made use of in equations (XVIII) : — 



6=005 



'=W9E-''^'^ 



. (53) 



;?i=3800 

 Po=760 

 To these must be added the values 



^ = 13-596 



0-= 0-001, 



which are the same for all cases; and then in the first of the 

 equations (XVIII), besides the required value of W, the magni- 

 tudes V and P2 alone will remain undetermined. 



52. We must now examine the least possible value of V. 



This value corresponds to the case where the pressure in the 

 cylinder is the same as that in the boiler, so that we have merely 

 to put;?i in the place oip^ in the last of equations (XVIII) in 

 order to obtain 



In order at once to give an example of the influence of the 

 vicious space, I have calculated two values of this expression, 

 corresponding respectively to the cases where no vicious space 

 exists (e=:0), and where, according to supposition, 6=0-05. 

 These values, expressed as fractions of a cubic metre to one kilo- 

 gramme of vapour from the boiler, are 



0-3637 and 0-3690. 



The latter value is greater than the former, because, first, the 



