SECT, in.] CONDENSATION OF STEAM. 149 



steam is lost in heating it again at each stroke. The means of obtaining a 

 maximum of useful effect from condensing in that manner has been shown, 

 (art. 165.) 



287. To find the quantity of water for injection into an engine condensing in 

 the cylinder, the formula is the same as when a separate condenser is used, the 

 difference being in the quantity of steam required ; and the water for condensation 

 is greater than when Watt's condenser is employed by 



14 (T - 



x t 



for each stroke, 



i being the weight of the mass of iron contained in the cylinder. 



288. The following tabular view of the modes of condensation may perhaps 

 present the subject to the reader in a clearer view than any other kind of con- 

 cluding summary. 



Steam may be f 1- * the vessel where its power is exerted { J^ m 1698 ' 



< I JVewcomen m 170o. 



IS. in a separate vessel Watt in 1769. 



f 1. by projecting a cold fluid against the vessel containing it Savery. 



I 2. by injecting a cold fluid among it Newcomen. 



Steam may be J 3. by exposing it to large surfaces of cold fluids or solids ( att< 



condensed I Cartwright. 



4. by the pressure of cold fluids against the vessels containing it Perkins. 

 l_5. by the union of two or more of these methods. 



