284 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
its ca]iacity is 2,000 gallons per day; the daily consumption of water on board is 
about 250 gallons. A ton of coal will distill about six tons of water, so there is a 
saving of weight and space by employing the distiller on board ship. The quality of 
the divstilled water is always the same, and I quote the words of an eminent medical 
director of the Navy in saying that “diarrhea has diminished 50 per cent on board 
onr ships since the introduction of distilled water.” The water is clear and, being 
well aerated, tastes quite as good as hydrant water; in fact it is dithcnlt to detect it 
as the product of distillation, particularly since the evaporator came into use in 
connection with this apparatus. 
BAIRD’S EVAPORATOR. 
This valuable adjunct to the condensing a])paratus has greatly improved the 
quality of the drinking water, besides iiroviding fresh feed for the boilers. Out 23 
shows a sectional elevation of the Albatrosses evaporator, known as No. 3, Type 0. It 
has a cylindrical shell of steel 2 feet 0 inches in diameter and 7 feet in height. On 
one side is a cast-iron door and frame, the former containing a steam chest in which the 
ends of the copper tubes terminate. But one joint need be broken in order to remove 
the tubes for cleaning. They are shown iiartially withdrawn. 
The method of operation is as follows: Sea water is pumiied into the evaporator 
until the tubes are covered; live steam from the boilers enters at the top of the steam 
chest, the lower end draining to the hot well. As steam forms from the sea water it 
ascends through the bafde plate to the steam pipe, and thence to the distiller, or 
main condenser, according as it is to be used for drinking purposes or for boiler feed. 
Excellent results have been obtained from its use on board the Albatross. 
THE STEAM WINDLASS AND CAPSTAN. 
This machine is commercially known as the “ No. 4, Providence capstan windlass,” 
and was built by the American Ship Windlass Company. It is situated under the 
forecastle on the main deck. The windlass portion consists of a horizontal wrought- 
iron shaft, mounted in journals on cast-iron frames, and carries two gypsy heads, a u, 
two cam-clutch wheels, d d, a bevel gear-wheel, and a spiral gear-wheel, which are 
keyed to the shaft; it also carries a pair of wildcats, h 5, and friction-brakes, c c, 
which are not keyed to the shaft. The bevel gear communicates motion to or from 
the capstan, and maybe uncoupled by unkeying the pinion; the spiral gear is for 
communicating the motion of the engine to the windlass. By revolving the cam- 
wheels d d a fraction of a revolution they are couiiled to the wildcats h b, by which 
means the wildcats may be made to revolve with the shaft at pleasure, and by this 
means the chain maybe veered to one anchor while the other is hoisted; both maybe 
hoisted or both veered while the engine is iu motion. The capstan is on the forecastle 
deck and is keyed to the shaft or spindle /. This capstan, which is revolved through 
the bevel gears, is used for catting and fishing the anchors, for hauling upon hawsers, 
hoisting boats, etc. (See jdate xii.) 
The engines are placed horizontally beneath the forecastle deck. They rotate in 
the same plane, are placed at an angle of 90°, and act upon the same crank-pin. They 
have locomotive slide valves actuated by “loose” eccentrics, by which means the 
engines are reversible. The cylinders and their respective cross-head guides are in 
one casting, while the outer cylinder heads only are movable. The cylindeis are 
