DEEP-SEA EXPLORATION. 
2<S5 
sufficiently large to hoist both anchors at ordinary depths of water, witli 10 or lU 
pounds of steam per s(piiirc incli of piston, and for this reason a- pressnre-regnhitiiig 
valve (cut 24) is placed in the steam-pipe; by tightening or slacking the screw the 
steam is adjusted in the cylinders to any pressure inside the limit of the boiler pressure. 
The engine takes its steam from the main boilers, and exhausts into the main 
condenser or into the atmosphere, as desired. 
Tlie engine makes from 275 to 325 revolutions per niiimte; at 300 revolutions the 
velocity of the starboard chain would be 4 fathoms per minute and the port chain 
3.4 fathoms per minute. 
LIGHTING. 
The Albatross has an electric plant for both internal and external lighting; also a 
complete outfit of oil lamps for burning mineral sperm. She was the first United 
States Government vessel to receive an electric installation for internal illumination. 
The original Edison electric plant furnished the vessel in 1882 consisted of a Z 
dynamo having a B circuit of 51 volts, driven by an Armiugton & Sims 8^ by 10 
inch engine, which, at 350 revolutions, drove the dynamo 1,700 turns per minute and 
furnished ample x>ower and uniform speed. 
There were 120 8-candle incandescent lamps in circuit, also a powerful arc lamp, 
which was run on the same circuit and used when a concentration of light was 
required at the table sieve to facilitate the work of the naturalists. The dynamo was 
rated at 1,200 candles by the makers, but was capable of developing much greater 
})ower. A new electric plant was installed in 1887, Avhich reiiresented the improve- 
meaits of five years. It consists of a Uo. 3 dynamo, with an A circuit of 110 volts, 
driven by an Armington & KSims OJ by 8 inch engine (cut 25), which at 300 revolutions 
drives the dynamo 1,200 turns per minute. 
The dynamo was rated by the makers at 1,200 candles, yet it develops nearly twice 
that power without visible evidences of distress. There are at the present time 152 
IG-candle incandescent lamiis in circuit, besides several portable hand lamps, Avhich 
are connected as occasion requires. Of course, the lamps are never all in use at the 
same time, seldom more thau half of them, the installation furnishing all the current 
needed. 
The governor of this engine is fixed to the dy wheel, which is keyed to the shaft, 
and consists of two eccentrics, one within the other, each moving independently upon 
