During the building construction they successfully 

 stood continuous overloads of from 50 to 75 per cent, 

 without sparking or injurious heating, conditions 

 being especially unfavorable, due to the unavoidable 

 presence of dust and dirt incident to the building 

 operations. 



Electric power has proved a vital factor in the de- 

 velopment of the modern office building. Many 

 problems where power is required 

 would be difficult if not impossible 

 of solution were it not for the 

 adaptability and flexibility of the electric motor. 



When office buildings were moderate in size the 

 number of persons occupying them was comparatively 

 small. Under such conditions natural means could 

 be depended upon to provide ventilation which, while 



ELECTRIC 

 MOTORS 



by no means adequate, was the best that could be ob- 

 tained. With development and gradual increase in 

 size, problems were introduced on the solution of 

 which depended the success or failure of the building. 

 The mammoth structures of the present day accom- 

 modate many thousands of persons, making the 

 question of ventilation of supreme importance. Many 

 cases arise in planning for ventilation where natural 

 means are inadequate and mechanical means must be 

 provided. Proper machinery must be placed in sit- 

 uations that are inaccessible and remote from the 

 source of power. The electrically driven fan or 

 blower is perfectly adapted to such conditions because 

 it can be placed in any position without regard to 

 other apparatus. 



Other problems arise, the great importance of 

 101 ] 



