DEEP-SEA EXPLOKATION. 
2G9 
steering wheel; its partitions or ribs divide it into three valves (one for each cylinder), 
though it is one casting. Tlie exhaust is delivered into the steam-tight l>ox which 
incloses the engine, aud all the oil which the crank-pin and crank-shaft journals ever 
receive must come with the steam worked through the cylinders. The mechanical 
performance of the machine is all that can be desired. The engine starts the moment 
the wheel is moved and stops with equal promptness; the power of the machine is 
ami)le and it is comparatively light and compact. 
A uxiUary steering-gear : This powerful screw gear is used when it is thought 
necessary to put the vessel stern to a heavy sea, as in sounding, and is designed to 
hold the rudder rigidly, thus relieving the ordinaiy steering-gear from unusual 
strains. It locks the rudder seciirely, aud is also an efticieut steering-gear which can 
be connected in a moment, aud as quickly disconnected. A compass is conveniently 
placed in the cabin skylight to steer by when the after- wheel is used. Cut 3 is a 
longitudinal elevation, and cut 4 a plan view of the apparatus. The yoke e is keyed 
to the upper end of the rudder-stock /, and the arms d, which have a screw-thread at 
one extremity working on the right and left hand screw-shaft i, and a hole in the 
opposite extremity for the reception of the pins u, are the means of connection between 
the yoke c, the screw-shaft i, aud the steering-wheel 1. 
The arms d are held in a horizontal position by the guide-rod e, which is 
supported by the adjustable bearings A-, which also carry the screw-shaft. 
To disconnect the gear, remove the pins a from the arms d and the slots fc, when 
the rudder will move freely. 
Spare tiller: Cut 3 shows the spare tiller g keyed to the rudder-stock /. The 
eyebolts li for the relieving tackles slide along the whole length of the tiller, aud are 
usually carried at the forward end for convenience in hooking in case of accident to 
the steering-gear. 
Rudder chains: The rudder chains are shackled to the short tiller projecting 
from the rudder, seized to an eyebolt in the stern, and carried along the quarters in 
the usual manner. 
