PY 
TRANSACTIONS OF THE SECTIONS. 187 
In conclusion, it was urged that the tangent-wheel was applicable to many falls in 
which the adoption of the water-wheel was not only unsuitable but impracticable ; 
and that much water-power which was at present wasted, might be utilized by means 
of it. It was applicable to all kinds of work, and might be used for agricultural pur- 
poses with great advantage. 
On the Want of Facts respecting the Performance of Vessels at Sea. 
By Admiral Moorsom. 
The author had himself arrived at results both in speed and in power for a great 
variety of types which appeared very near the truth ; and if a similar method of inves- 
tigation were applied to carry out experiments conducted at sea under a vast variety 
of conditions as to form, size, and circumstances, rules might be established which 
would serve to determine much of what was now the subject of controversy, and go 
_ far to remove the reproach on the greatest maritime nation of the world, which was 
contained in the following passage cf a work by Mr. Scott Russell :—“ It is admitted 
that out of every three steam-vessels that are built, two fell very far short of fulfilling 
the intention with which they were constructed.” 
Improvements in the mode of Working Steam-Engines. By T. Moy. 
| By drawings the author showed how he proposed to work steam-engines. No. 1 
was an elevation plan and cross section of a pipe-boiler. ‘The boiler is composed of a 
continuous tube, which may be arranged as in the drawing or in any other efficient 
_* mode, and is always kept full of water. By the circulation of the water, the cylinder 
is always kept at the same heat as the boiler. The heated water circulates through 
the boiler, jacket, and valve-box of the cylinder; the upper and hottest end of the 
tube communicates with the upper part of the jacket, and the lower end of the tube 
carries the cooled water back to the boiler. An open communicaticn is maintained 
in any convenient place or places between the jacket and valve-box. The slide-valve 
(Drawing No. 2) has three cavities in it. The upper and lower cavities are for 
receiving and delivering the necessary quantity of water from the valve-box to the 
 steam-passage. The middle cavity is for the eduction. Before the water-cavity of 
the valve arrives with its supply of water at the steam-port, its communication with 
the valve-box is cut off, and this portion of water turns into steam and works the 
piston. In the drawing No. 2, the upper water-cavity is shown as having arrived 
opposite the upper passage and the piston has just commenced the down-stroke, 
while the used steam under the piston is passing off through the eduction. The 
_ throttle-valve and regulator must be on the eduction. i 
The author mentions a plan for controlling the number of inches of water supplied 
to the cylinder at each stroke without stopping the engine. The engine always 
_ works expansively. 
_ Suppose an engine, the internal capacity of whose cylinder is equal to 3 cubic feet, 
to be supplied by the valve with 3 cubic inches of water at 500° Fahr. As soon as 
this is at liberty to enter the cylinder it begins to turn into steam, which will drive 
the piston until all the water has turned into steam; from this point of the stroke to 
the end the steam will work expansively, and at the end of the stroke will be just 
equal to the pressure of the atmosphere. By its then passing through the eduction 
into a surface condenser (without injection, and without attempting to obtain a 
-yacuum), it can be condensed to water and returned to the boiler. 
_ Suppose this engine to be used in a factory. If it is required to reduce the power 
of the engine in consequence of some of the work being thrown out of gear, this may 
be done in two ways—by reducing the temperature of the boiler, or by reducing the 
tity of water supplied by the water-cavity of the slide-valve ; in the former case 
engine will work less expansively and with less pressure; in the latter more 
_ expansively and with the same pressure at the first portion of the stroke. 
_ By this mode of working steam-engines, great safety with increased pressure and 
mpactness may be obtained; incrustation of the boiler and priming of the cylinder 
l be prevented. 
