switches located near the entrance doors; for important 
rooms the switches are of the remote control type located 
in the cut-out cabinets; the momentary contact switches 
operating them are located by the desks of the attendants in 
charge of the rooms.
       The lights in the main aisles of the bookstack are 
located near the attendant's station and by the entrance doors; 
the lights in passages between the shelves are controlled by 
switches at each end of the passage, thus making the control 
of these lights so easy that there is no reason for burning 
more lamps than are absolutely necessary.
       As there are about five thousand outlets in the bookstack 
it is very desirable to have the control of the lights so easy 
that only those immediately adjacent to the books sought 
need be burning at any time. Tumbler switches were used 
everywhere.
       A receptacle was installed in each passage between 
shelves so that portable vacuum cleaners may be used for 
cleaning the books and shelves.
       In the work spaces and in all reading and some exhibition 
rooms, systems of fiber underfloor ducts were installed 
and circuits provided so that additional outlets may be put in 
to provide table or desk lamps, or for the illumination of 
exhibition cases.
       To provide proper protection for light and power circuits, 
sixty-one cut-out panels for lighting circuits and seven 
for power circuits were installed.
       The connected load in lamps is about 600 kilowatts, and 
there are forty-five motors of a total of 264 horse power. 
These motors drive elevators, pumps, fans, a pneumatic tube, 
and a vacuum cleaner system.
     Low tension systems. Under this head come such systems as telephone, clock, and signal systems for various 
purposes.
       A system of conduits is installed into which the local 
telephone company has pulled wires to sixty-four outlets and