134 



SCIENCE. 



[N. S. Vol. XVII. No. 421. 



south at the ends, and 58 feet in the cen- 

 tral portion. An extension of the base- 

 ment, wholly below the ground level on 

 the south, is 20 feet wide and projects 25 

 feet east and west beyond the main por- 

 tion of the building. This increases the 

 floor area of the basement by 50 per cent., 

 affording ample accommodation for the 

 mechanical plant on this floor. 



The boiler room is 42 feet square and 19 

 feet high, the floor being 5 feet below the 

 engine room floor, and, like the engine and 

 dynamo room, it is lined with white en- 

 ameled brick. Two water-tube boilers, of 

 125 horse-power each, are to be installed, 

 and space will be reserved for two other, 

 giving a final capacity of 500 horse-power. 

 The boilers will be fed by automatic 

 stokers, and induced draft will be fur- 

 nished by a pair of blowers, driven by 

 small steam-engines so governed as auto- 

 matically to hold a constant steam pressure 

 in the boilers. The smoke flue extends 

 only a little above the roof, and the fur- 

 naces will be operated to give as nearly as 

 possible smokeless combustion. Water and 

 air pumps, filters, boiler feed pumps, pres- 

 sure tanks and other auxiliary apparatus 

 will be located on a platform at the north 

 side of the boiler room, on the engine floor 

 level. 



The engine and dynamo room is 87 feet 

 long, and has an average width of 24 feet. 

 The end toward the boiler room will con- 

 tain two 80-horse-power high-speed steam- 

 engines, each directly connected to two 25- 

 kilowatt dynamos, each giving 200 

 amperes at 125 volts and connected in a 

 three-wire system, the total capacity, 

 therefore, amounting to 100 kilowatts. 

 Space is reserved for a third engine of 

 160 horse-power, to drive generators of 100 

 kilowatts capacity. The western half of 

 this room will be occupied by a number 

 of alternating-current dynamos directly 



driven by electric motors. These will fur- 

 nish singiephase and polyphase current for 

 experimental purposes. Several such ma- 

 chines are now being constructed, and 

 others are yet to be ordered. There will 

 be machines with smooth-core armatures 

 and specially shaped pole pieces to give 

 sine waves, others to give distorted waves, 

 and still others to give several harmonic 

 waves which may be combined in various 

 ways to give different wave forms. On the 

 south side of the engine room a switchboard 

 will carry the controlling apparatus for 

 all these dynamos and motors, and also 

 for several storage batteries, and for dis- 

 tributing current to the various labora- 

 tory rooms of both buildings. Both live 

 and exhaust steam pipes will be located in 

 the subbasement under the engine room 

 floor. 



The refrigerating room is 41 X 18 feet, 

 and wiU contain an ammonia refrigerating 

 machine, a liquid-air machine, and a small 

 ice-making plant. The refrigerating ma- 

 chine will have a capacity equivalent to 

 the melting of thirty tons of ice per day. 

 A large tank, filled Avitli calcium chloride 

 brine, will be placed in a room in the sub- 

 basement just under the refrigerating ma- 

 chine, and will enable 'cold' to be stored 

 equivalent to ten tons of ice. This may 

 be used at night, when the refrigerating 

 machine is not running, or may be used to 

 supplement the machine in the hottest part 

 of the day, if necessary. 



The storage battery room is 61 feet long, 

 and will contain several batteries, which 

 will furnish current to motors driving 

 alternators, ventilating fans, the machines 

 of the instrument shop, lights in the build- 

 ings when the engines are not running, and 

 current for experimental purposes. 



The air-cooling chamber will contain a 

 large quantity of iron pipe through which 

 cold brine will be pumped, and the air to 



