218 CARNEGIE INSTITUTION OF WASHINGTON. 



during periods of interruption of the service. This large supply of 

 power has been of the greatest value, in view of the heavy demands 

 of some of the construction work upon the 100-inch telescope. Since 

 much of the electrical energy of the Edison Company is obtained from 

 hydrauhc installations, the use of this source of power is most desirable, 

 in view of the necessity for economy in all kinds of fuel at the present 

 time. 



As in previous years, Mr. Dowd, engineer in charge of the power- 

 plant, has built and installed most of the additional electrical equip- 

 ment. This has included the large switch-board and automatic 

 switches for the Pasadena laboratory; numerous electrical controls for 

 the operation of the 100-inch and the 150-foot tower telescopes; and 

 the rearrangement of much of the apparatus and connections in the 

 power-house for use with the transmission line. 



