282 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
and has at its center a piston valve; steam enters throngh the end of tlie piston 
valve, and by moving this valve the steam goes to one side of the chest only; by 
moving the valve in the oiiposite direction the steam would go to the other side of 
the valve chest, which latter is divided, by a longitndinal diaphragm, into two com- 
partments; the exhanst is throngh one side of the piston valve. By this arrangement 
it will be seen that when this piston valve is in its middle position no steam can pass 
into or ont of the engine, which, of course, stops it; it is also manifest that a movement 
of the valve in one direction will cause the engine to run in one direction, and the 
opposite motion of the valve will reverse the engine. The iiiston valve is moved by 
a lever which has a long slot in it (a, cut 21) through which the hoisting roi)e 
])asses; on the rope there are two stops (knots), so situated that one will press and 
move the lever when the bucket A- is up, and the other when the bucket is down. 
To operate the machine two men are employed; the lirst one tills the bucket and the 
second one moves the lever, the bucket rises to its stop and is brought to rest; the 
second man dumps the bucket into the chute, and pulls the lever, when the bucket 
descends to the tioor and is again automatically stopped. The machine is noiseless 
and rapid in its action, works with certainty, and requires but little attention. 
COAL BUNKERS. 
The boilers are fore and aft on the midship line, and wing bunkers extend the 
whole length of the boiler space, 40 feet in the hold and 32 feet above the berth deck, 
on both sides, from the door to the main deck. The forward and after sections are 
connected by arches over the boilers. The capacity of the Aving bunkers is 125 tons. 
The forAvard bunker lies betAveeu the boiler space and laboratory store-room; it 
extends from floor to berth deck and across the Avhole beam of the vessel, Avith a 
capacity of 40 tons, a total bunker capacity of 175 tons of bituminous coal. There 
are 8 coaling scuttles, 4 on each side, at convenient intervals on the main deck. 
An auxiliary bunker has been improAdsed upon seA^eral occasions from the labora- 
tory store-room by removing from it everything except the inclosed lockers, Avhich 
were protected by rough boarding, leaving stowage room for 45 tons, in bags; and a 
gain of 15 tons could be elfected by removing the lockers. Coal canied in this siiace 
is passed through the laboratory hatch. A deck load of 25 tons may be safely carried 
in bags, giving a total coal capacity as follows: 
Winij Bunkers tons.. 125 
Forward bnuker do... 40 
Auxili.ary bunker, bagged do... 45 
Deck load, bagged do. . . 25 
Total coal ca])acity do... 235 
The auxiliary bunker can be utilized only by landing a portion of the scientific 
outfit. The steaming radius, with 235 tons of good bituminous coal, a fairly clean 
bottom, and good weather, is 4,500 miles at an 8-knot speed, Avhich can be maintained 
on a consumption of 10 tons of coal per day. 
BAIRD’S FRESII-AVATER DISTILLING APPARATUS. 
The distiller (cut 22) is patented by the inventor. Chief Engineer George W. 
Baird, U. S. 1ST., and is the form generally used on board American steamships. 
The object of the ap])aratus is to distill drinking Avater. There are three block-tin 
coils placed inside an annular cast-iron cylinder, the coils terminating in manifolds 
