BOILER TESTS. 



INTRODUCTION. 



In the pursuit of his business as a steam engineer the author 

 has had frequent occasion during the past ten years to make 

 evaporative tests of steam boilers. The interests which have 

 led to the work are of a varied character. Inventors or build- 

 ers of new types of boilers have been desirous of learning 

 what economical features their improvements possess, and they 

 have called for the results of an evaporative test as a means of 

 comparison with the performance of existing boilers ; 01% know- 

 ing themselves the economy of the improved generator, they 

 wished, for purposes of trade, to corroborate their own testi- 

 mony of its superiority, by the certificate of a disinterested 

 engineer. Managers of factories have sought advice upon the 

 cause of excessive consumption of coal in their steam plants. 

 To solve this problem it is necessary to ascertain the evapora- 

 tive efficiency of the boilers, so as to separate the process of 

 generating the steam from that of its use after generation. 

 They have also desired information upon the general economy 

 of their boilers, and upon the kind of fuel which it would be 

 most advantageous to burn, when all the questions of current 

 price, evaporative efficiency and incidental advantages and ob- 

 jections are taken into account questions which can be deter- 

 mined satisfactorily only by means of an evaporative test. 

 They have had occasion, too, before completing a settlement 

 with the contractor for a new plant of boilers, to call for a test, 

 to ascertain whether in capacity or economy, or both, the boil- 

 ers do their work in the manner stipulated in the contract. 

 They have also sought information, which only an evaporative 



