558 
STEAM 
liquid contained therein, being reduced to the lower tem¬ 
perature, the elasticity of the gas is then at its minimum; 
but which will at all times be very considerable, especially 
if the carbonic acid, or the nitrous oxide, are the liquids em¬ 
ployed ; a flood of hot oil suddenly descends upon and sur¬ 
rounds the generator; instantly an evolution of gas takes 
place, and continues till its elasticity, pressing on the oil in 
the gasometer, causes the latter to rush into the cylinder, 
and carry with it the piston that works therein, to the further 
extremity. The duplication of the apparatus produces the 
return stroke, and thus an alternate movement is kept up. 
But to effect the re-action, the elasticity of the gas, which 
now occupies nearly the whole of the gasometer, must be 
reduced. For this purpose, the generator is flooded with 
cold water, which rises from below, bearing up the hot oil 
on its surface to the place from which it descended. The 
temperature of the generator and its liquid falls, the gas con¬ 
denses rapidly on its extensive surface ; its density as rapidly 
diminishes, it returns to its first elasticity, and the oil regains 
its former level in the gasometer. Again the water sinks, 
and the hot oil descends, and thus the same vessel becomes 
alternately a boiler and a condenser; in one case generating 
a gas, in the other a liquid. 
“ To force up the hot oil from the alternator into the ealo- 
rator, in which it is heated, a plunger is immersed in the 
column of cold water contained in the refrigerator; this 
raises its level, and consequently the level of the column of 
water and oil with which it is in equilibrium. There is not 
the friction, concussion, or elaborate workmanship, which 
would attend a piston employed for this purpose. The 
specific gravity of the oil being less than that of water, 
there will of course be a difference and a varying difference 
in the altitude of the two columns when in equilibrium, ac¬ 
cording to well-known hydrostatic principles, but this is of 
no consequence. The plunger must be so proportioned, and 
immersed so deep, as to displace a body of water equal in 
volume to that of the oil elevated, besides what is required 
for the raising of its own level. Now it is obvious that here 
is an opportunity to regulate the power of the engine, for 
the less the plunger is raised the less is the descent of the hot 
oil, and consequently less of the liquid is exposed to its 
influence; a governor, therefore, would be very properly 
applied to the movements of the plungers. If a greater 
power is required than when the governor is at the extreme 
limit of its influence, that is, when the generator is entirely 
surrounded with hot oil, it may be produced by bringing 
the lamps nearer to the calorator, or by lighting a greater 
number of them. If, however, the same velocity of action 
is not required to be maintained, the engine, possessing in 
itself a source of self-regulation, will increase in energy for 
the occasion ; because the slowness of the strokes, allowing 
a longer time for the heating of the liquid, its temperature 
will be raised to more than the ordinary degree, for this 
must be always less than that of the hot oil The extent to 
which this enlargement of the power may be carried, and the 
facility with which it may be effected, is of great importance 
with respect to navigation, and will be duly fappreciated by 
those conversant with the subject. It should be observed, 
that the action of the plungers must be a little in advance of 
that of the piston, in order to give time for the heating and 
cooling of the metal of the generator. There is this peculia¬ 
rity in the engine, that it has neither valves, cocks, nor 
pumps, nor any moving joint, except that of the piston and 
its rod; hence its simplicity, and consequently the cheapness 
with which it may be constructed. The room which an 
eighty-horse power engine would occupy, would not proba¬ 
bly be more than a cubical space of seven feet dimensions, 
so far as its cylinder and appendages are concerned. It 
would be quite practicable to attach a gauge to the engine, 
by which the pressure of the gas may be ascertained ; and 
means are devised by which the height of the liquid in the 
generator may be known. The introduction of the carbonic 
acid, or other liquid employed, should be in the form of gas. 
For this purpose, the generator must be brought to a lower 
ENGINE. 
temperature than the gasometer, which will occasion the 
greater part to condense therein; that which may form in 
the gasometer will distill over, after the apparatus for pro¬ 
ducing the gas is removed. It is also for this reason, that 
there is no fear that an accumulation of tlie liquid will take place 
in that vessel during the working of the engine. To pre¬ 
vent condensation, however, in any hurtful degree, its inte¬ 
rior is lined with wood, and a board floats on the surface of 
the oil. Another plan would be, to maintain the gasometer 
at the higher temperature to which the liquid is raised ; but 
this is by no means advisable if it can be avoided. Tire 
board is also of important use, in preventing the absorption 
of gas by the oil, during the greater pressure; which being 
evolved at the time of the collapse, would prove injurious* by 
diminishing the difference between the elastic forces. Oil is 
selected as the heating medium, because it is lighter than 
water, and has its boiling point so much higher. It is pro¬ 
bable, however, that 212 degrees is a temperature sufficiently 
superior to that which the liquid will require to be raised, 
and such as will produce its almost instantaneous heating ; 
if so, hot and cold water may be employed. From the rela¬ 
tive position of the two mediums, little communication of 
heat can take place. The alternator is internally lined with 
wood, partly to prevent a loss of heat, but principally to 
preserve, as much as possible, the coldness of the water. In 
a locomotive engine, the water could only be occasionally 
changed; in the intervals, a cooling process may be at work, 
and the plungers w'ould perform the office of a pump.” 
The next of modern engines we feel it requisite to describe 
is, Mr. Eve’s patent engine. We shall borrow in part his 
own description. He informs us, that he lays claim to 
improvements in the five following particulars:— 
I. The application of revolving cones to rotary engines* 
for the purpose of compensating any loss by friction. 
II. A steam generator so constructed of tubes, that the 
heat of the furnace shall cause the water to circulate con¬ 
stantly through these tubes, so that they shall be less liable 
to burn out or become oxidated. 
III. An arrangement of one or more revolving cock or 
cocks, for the purpose of supplying the generator with water; 
in lieu of the ordinary forcing-pump. 
IV. A new safety apparatus, by which the elasticity of 
steam in boilers is ascertained by weight applied directly in¬ 
stead of indirectly, as with the ordinary steel-yard valve. 
V. An arrangement of cog-wheels, with a compound en¬ 
gine in such a manner, that the steam after having acted as 
high pressure, may be used with low pressure, with greater 
effect than in any engine now in use. 
The manner in which each of these improvements is ef¬ 
fected, we shall now proceed to explain ; taking the speci¬ 
fication of the patentee for our guide. 
I. The revolving Cones. —Fig. 2. PI. III. presents an 
end section ; and fig. 3, a longitudinal section of this part of 
an engine, constructed according to Mr. Eve’s simplest man¬ 
ner.— a a are the cylinder and cone, revolving in contact in 
opposite directions, the cone, having one groove, and being 
one-third of the diameter of the cylinder, which latter has 
three wings or pistons, c cc, the ends of which, as they re¬ 
volve, touch the outer case, e, and do not admit any steam 
to pass. The steam is admitted through the pipe f, and 
acting on the wing e, causes the cylinder to revolve until 
the said wing passes the pipe, g, where the stratum of 
steam lodged between each two wings is allowed to escape; 
the wing which has thus passed, falls into the groove d, of 
the cone, the bottom of which groove touches in passing, 
thus allowing no steam to escape between. The said wing, 
c, then passes again by the steam-pipe, f, and is acted upon 
as before described, and so in rotation. The cylinder, .a, 
which is firmly fixed to its axis, h, rests on one side, on the 
outer case, e, through which the axis projects; but as there 
is some friction produced by the revolution, of the said cy¬ 
linder at its two ends, touching the outer case, Mr. Eve 
has placed a false end, h h, under the opposite end of the 
cylinder, which false end slides on the axis, l>, freely, and 
