274 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
BOAT-DETACIIING APPAUATUS. 
The wliale-boat aud dingey are ke]tt hanging at the davits ready forenierg encies, 
and are i)rovided vith a unique detaching apparatus (plate ix), the invention of Lieut. 
William Maxwell Wood, U. S. N. 
The object of a detaching apparatus is to disengage both ends of a boat from the 
tackles at the same time, the operation being under the control of one man. To 
accomplish this Mr. Wood has provided a pair of links, L, ligs. d and f, which oscillate 
freely about a «}euter of motion. The form of this link is such as to permit the spherical 
toggle T to iiass between its sides: now, if the link is pulled down by the chains rr', 
and the ends of the chains connected by the slip hook h, the toggle will slide up in the 
link and be locked in the narrow S[)ace between its sides, as shown in full lines in hgs. 
1, 3, and 4. If, however, the slip hook h is tripped by pulling the lanyard a, figs. 1 
and 2j both chains rr' will be slacked, and the links L released to lly up into the posi- 
tions shown by the dotted lines in fig. 1, releasing the toggles and thus detaching the 
boat. The locks p are provided as a measure of safety to prevent the toggles from 
sli]q)ing out of the links in case one end of the boat is hoisted faster than the other, 
or a fall is accidentally let go; in fact, they prevent either end from being detached 
until tlie links are released by pulling the lanyard a. 
This simple opparatns has been in constant use, at sea aud in i)ort, under all 
conditions of wind and weather, aud has answered its iiurjiose admirably without 
a single failure or accident. 
STEAM MACHINERY AND ITS ACCESSORIES. 
There is a two-cylinder conq)Ouud engine for each of the two propellers; the 
engines are independent and are provided with steam reversing gears; they are 
u[)right, but not vertical, the cylinders inclining toward each other to give more room 
on the working-platform. There is one condenser, common to both engines, which is 
mounted on a bed-])late, aud which forms the framing and cross-head guides for the 
engines; the single bed-idate supports the pillow-blocks of both engines. The con- 
denser is of the type known as “surface condenser,” and is arranged in three nests of 
horizontal tubes, the water passing successively through each nest, and the steam is 
condensed on the outside of the tubes. 
There are two plunger air-pumps, placed horizontally forward of the main engines, 
one plunger being worked from a concentric on the forward end of each crank-shaft. 
Both i)umps are in one casting. The feed-pumps are worked from rods extending from 
the air-pump plungers. 
The valves of the high-pressure cylinders are locomotive slides, over which gridiron 
cut-olf valves are placed, while the low-pressure valves are double ported and are 
without cut-offs. All these valves are actuated by eccentrics aud Steiihenson links, 
in the usual manner. 
The engines are provided with a system of valves by which they may be converted 
from compound to single expansion or simple engines. There are two outboard deliv- 
eries, one for the circulating water and one for the air-pump or fresh water. 
The circulating i)ump is a Davidson light-service pump. No. 26 (cut 19). 
