DEEP-SEA EXPLORATION. 275 
Tliere is ;i Hexible coupliiij;- comiectiiig each crank sliaCt to its line sliaft, and the 
tliriist l)eariiigs are on the liiieshalts. 
The serew propellers are ri<>ht and left, with four blades each. 
The shaft brackets are of wrought iron; one is placed near the hub of the screw 
and the other halfway between this and the hull. The Journals of the brackets are 
lined with bronze and lignuin-vita', and the shaft in these Journals is covered by a 
bronze Jacket in the usual way. 
The stern pipes are of cast iron, the after lloors being bored to receive them, and 
the frames bent round them. The stern bearings are likewise of cast iron, with 
flanges fitting the hull; they are 3 feet 4 inches in length, are lined with lignum-vita' 
staves, and are recessed to receive the stern pipes; the usual stuffing boxes are 
provided. 
The sea valves are of bronze with bronze stems, seats, and glands, with cast- 
iron chambers, and have outside threads. 
There are two escape ]>ipes, one for each boiler, and a steam whistle forward 
of the smokestack. The exhaust from steam radiators and all auxiliary machinery 
is carried to the main condenser, the hot well, or to the atmosphere through the 
escape pipes, as preferred. 
Engine signals are made by ordinary bell pulls on the bridge and in the pilot 
house, connections being made to gongs on the engine room platfonu by means of 
wires and bell cranks. 
There are three gongs, the large or main one in the center, a small one on the 
jtort side, and another of the same size, but of different tone, on the starl»oard side of 
it, all inclosed within a brass hood which is connected with a return sounding tube 
to the pilot house. Verbal orders are transmitted through a speaking tube having 
branches to the bridge, the pilot house, and sounding machine. 
The following are the engine signals in regular sequence, both engines being at 
a stand, and to be worked together as one: 
1. .Jingle bell. — Cautionary. Stations for working the engines. 
2. (*)ne bell, main (gong). — Ahead slow. 
3. .Jingle J)ell. — Full speed. 
4. One bell, main. — Half sjieed. 
5. One bell, main. — stop. 
6. Two bells, main. — Raek, ordinary full speed. 
7. .Jingle bell. — Back hard, open throttle. 
8. One bell, main. — Stop. One Jjell always stops a backing engine. 
9. .Jingle bell, with, engines at a stand. — Have tinished with the engines. 
The foregoing sigJials apply also to the starboard and port engines when they are 
worked independently, their respective gongs being used. 
lUmtratire example. — The vessel being underway and both engines at a stand, to 
furn sharp to starboard: 
1. One bell jjort, two bells starl)oard. — Helm hard aport; engines worliing alike at half sj>eed. 
2. Jingle bell. — Full speed; port ahead, starboard J>ack. 
3. One bell, main. — Slow]sort, stop starlioard. 
4. One Irell port. — Stop jmrt engine. 
Modifications of speed other than half or full power are effected through the si^eak- 
ing tube. 
