PREFACE. 



THE favor with which the author's book on "Boiler Tests," 

 published in 1891, has been received, has led him to collect in 

 similar form the data and results obtained on many of his 

 engine tests. Some of the tables of results have appeared 

 from time to time in mechanical journals and in pamphlets ; 

 also in the Transactions of the American Society of Mechanical 

 Engineers, but a large part is now printed for the first time. 



It is believed that the data here presented will prove of 

 value to the engineering profession, to owners and intending 

 purchasers of steam plants, and to any who are interested in 

 the economical production of power. The book should be of 

 special value to engineers advising intending purchasers of 

 engines, on account of the assistance it will render in making 



a wise selection. 



GEO. H. BAKKUS. 



1)5 MILK STRKKT, BOSTON, March, 1900. 



