SSA WILLIAM SIEMENS, F.R.S. ~ 



960 + (212 110) 



= 2T2 Ibs. of water to condense 1 Ib. of 



ll(i 00 



steam, in place of the 6'4 Ibs. which the regenerative condenser 

 requires. In the case of a locomotive or other high-pressure 

 engine, where the steam is released from the cylinder at a pressure 

 of say 80 Ibs. above the atmosphere, two-thirds would be allowed 

 to escape uucondensed, and the vacuum would be obtained with 

 only G'4 -* 8 = 2*13 Ibs. of condensing water for every 1 Ib. of 

 steam passed through the cylinders. The small quantity of con- 

 densing water required renders the regenerative condenser ap- 

 plicable to engines in nearly every locality ; and pains have been 

 taken to render the apparatus itself equally light and compact. 



The advantages resulting from the application of the regenerative 

 condenser to high-pressure engines are as follow. 



1. Additional effective power, gained on account of the vacuum. 

 The indicator diagram, Fig. 3, Plate 2, illustrates this gain, 

 which, supposing the average steam pressure to be 40 Ibs. above 

 the atmosphere and the vacuum within the cylinder to be 10 Ibs., 

 amounts to 20 per cent, irrespective of expansion. If both the 

 steam pressure and the work on the engine remain unchanged 

 after the condenser is applied, it is evident that the steam may be 

 worked expansively to a large extent without diminishing the 

 absolute driving power of the engine. 



2. Heat saved in generating the steam, by the use of boiling-hot 

 feed water ; and the remaining portion of the hot water may be 

 advantageously used for heating buildings, dyeing, &c. High- 

 pressure engines are frequently provided with heating apparatus 

 for the feed water, which heats it on the average to about the 

 temperature of the condensing water from low-pressure engines, 

 or 110 Fahr. The regenerative condenser heats it to 210 Fahr., 



which constitutes a saving of -- r - = about 10 per cent. 



When such heating apparatus is not provided, the saving amounts to 



210- GO 



= about 15 per cent. 



3. The steam which is not condensed may be used to cause a 

 draught in the chimney, or for other purposes. 



4. The displacing cylinder, unlike the air pump of the injection 

 condenser, abstracts no motive power from the engine. 



