group who assume the responsibility for the proper 

 completion of the test. The switchboards must be wired 

 so that a large number of connection combinations 

 can be readily obtained. The instruments used must be 

 of the highest quality to insure accurate results, and 

 must frequently be compared with reliable standards 

 work for which a standardizing laboratory is necessary. 

 All these matters must be kept in mind and a system 

 provided for enforcing testing regulations for obtaining 

 clear records of the work done. In short, the testing, 

 department is a complex organization whose keynote is 

 efficiency. Economy of labor and power, and the 

 arrangement of apparatus are of equal importance with 

 accuracy; with the latter, of course, a sine qua non, 

 since the majority of apparatus tested must meet 

 specification as regards performance, heating, efficiency, 

 and the like. When, as often happens, more than one 

 method can be employed in a given case, that test must 

 be chosen which yields the maximum of accuracy 

 practicable, consistent with the character of the work. 

 These questions are fully considered in this little book 

 and will appeal to all those having charge of similar 

 departments, college laboratories, etc. To the student 

 of engineering, however, the description of the various 

 tests, their preparation, how they are carried out, the 

 instruments used, and the diverse calculations required 

 will appeal most strongly. Nearly all types of electrical 

 machinery have been covered, and many examples have 

 been given showing the kind of results that actually 

 obtain in the more important cases, and the means 

 employed for discovering electrical or mechanical faults. 

 EDITOR, GENERAL ELECTRIC REVIEW. 



IV 



