562 
STEAM ENGINE. 
The form and disposition of the paddles might certainly 
be improved. They seldom strike the water in the right 
direction, but splash it about, and leave it to impede the 
progress of the vessel. An irregular unpleasant motion is 
hence produced, and much force thereby lost. With a 
strong side-wind likewise, the larboard paddles are deeply 
immersed in the water, while the opposite ones are nearly 
suspended in the air, and scarcely act at all; the necessary 
consequence is, that, in such circumstances, the steam ves¬ 
sel describes a winding path, and becomes unmanageable by 
the helm. Proposals of various kinds have been made to 
obviate this defect; but though apparently ingenious, our 
practical engineers have not adopted them. 
Of the application of steam to the propulsion of land- 
carriages, we have given an example in the article Mecha¬ 
nics. The machine there described works by means of 
cogged wheels on a railway. On such a road it is easy to 
construct steam carriages that will travel with the most per¬ 
fect safety, laden with almost any weight, and capable of 
the utmost velocity than can be required. The great ex¬ 
pense of railways, however, has caused the use of these 
engines to be much circumscribed, and accordingly it has 
become a desideratum to construct a machine that could 
travel on the common roads. This is obviously very diffi¬ 
cult, on account of the numerous irregularities presented to 
the feet of the engine; irregularities clearly of such a nature, 
that they cannot be calculated. Many ingenious attempts 
have been made; but that which appears to us to be the 
best, is Sir George Cayley’s: he calls it his “ Patent Univer¬ 
sal Railwayat fig. 6, PI. I. it is seen. It is not furnished 
with its steam engine, but this is obviously easily added. 
This vehicle is formed by two endless chains, consisting of 
portions of a railway so jointed that they form an inflexible 
right line when resting on the ground, but each capable of 
coiling round a fore and hind wheel on one side of the wag¬ 
gon, and thus of revolving with them (see prefixed drawings.) 
Each joint carries with it a supporting piece or foot, which, 
in the engraving here given, is a small broad wheel, the line 
of its axle being parallel with the rail-chain. These, of 
course, give any required degree of lateral motion, but this 
movement is checked in the case of a road inclined towards 
one side, by a wheel placed on a hinged axle in such a man¬ 
ner as to operate laterally in the same way that a dray-pole 
does longitudinally when a carriage backs upon it: this 
wheel is not shown in the plate. Sledge-shaped feet are, on 
some occasions, substituted for these wheel-feet, particularly 
when broader supporting surfaces are necessary. Each link 
consists of a double frame of iron, with a space between 
them, so constructed as never to approach the two adjoining 
links within a couple of inches in any part but where the 
angular motion of the joint is stopped by a projecting piece 
of solid ash wood, resting on a flat face of iron (see A, fig. 7), 
where one link and its appendages are shown on an enlarged 
scale, and its connexion with the adjoining links by dotted 
lines. 
A, fig. 8, show's a portion of the interior structure of a 
link, with the bed for the oak piece. 
Fig. 9 is transverse section of the rail on a smaller scale, 
showing the mode of mounting the small wheels, each link 
being cast or forged in two pieces united longitudinally, by 
transverse bolts, B B, fig. 7. 
C, in fig. 6, is a wheel not touching the rail-chain, but 
close to its surface, to support the chain when exposed to 
violent strains. This rail-chain obviously adds considerable 
weight to a vehicle, and it can only be determined by ex¬ 
periments on a large scale, whether this evil is more than 
counterbalanced by the very advantageous mechanical pro¬ 
perties it possesses. 
It is obvious from the construction, that if this vehicle 
were pushed forward over a precipice, it would keep putting 
down its feet in an horizontal line in the air, till the line of 
direction from the centre of gravity passed over the edge, 
then the whole would balance over and fall together; but if 
another precipice at the same horizontal level were within 
reach of the leading foot before the vehicle did balance over, 
this foot would sustain the carriage in its path as correctly as 
if the way had been unbroken. Hence, as the hollow irre¬ 
gularities in bad roads will seldom, if ever, exceed half the 
length of the vehicle, these will not in the slightest degree 
affect the smooth course of the machine. 
With respect to hard points that rise above the ordinary 
level of the road, three out of four will be avoided in the 
space between the feet; and as the number of points on 
which the chain rests must keep it about the average or mid¬ 
dle height between the lowest and highest parts of the road, 
each elevated point that is hit by a foot will not cause more 
than half the immediate rise of wheel on the chain, that the 
usual depression on either side will give to an ordinary 
wheel on the road. 
In addition to these advantages, the elevation is converted 
into an inclined plane of the length of one link, upon which 
the fore-wheel ascends, and into a similar but reversed in¬ 
clined plane down which the hind-wheel descends, thus 
restoring the power required for the rise. 
The perfect practicability of using steam for all purposes of 
conveyance, has been no where so completely shown as on the 
Darlington and Stockton railroad. The engine used here, 
will travel over the 25 miles seven times a-day, making 175 
miles a day’s work, with 90 tons, consuming seven tons of small 
coals each day, or 42 tons per week; which, at an average 
cost of 7s., will be 14/. 14s. One man and a boy in con¬ 
stant attendance, supposing the 24 hours equal to three days, 
will be three men and thirteen boys each day, at 16s. 6r/., 
will add 51. 3s. 6c/., making the total weekly expense 
19/. 17s. 6d. The engine will cost 600/., 80 waggons 
900/., giving 1500/.-for the entire expense. 
Now, 90 tons will load six boats; each of these boats 
will be a day in performing 20 miles; therefore 52 boats, 
with 52 horses, 52 men, and 52 boys, will be required to 
execute the transfer of 90 tons 175 miles in one day; each 
horse will cost weekly a guinea, each man a guinea, and 
each boy 12s., forming a total weekly charge of 140/. 8s. 
in lieu of 19/. 17s. 6c/. The 52 boats and horses will be 
worth 10,000/., and requiring a considerably greater amount 
to keep them in repair; throwing a balance of full 7000/. 
per annum in favour of every locomotive engine that may be 
used. How many may eventually be at work it would be 
difficult to conjecture ; but as 40 would be required to work 
the London, Birmingham, and Liverpool, and the Manches¬ 
ter and Stockport lines, in all probability not less than 500 
would be employed: and, as the saving on every five 
engines would be equal to the interest of one million, the 
500 would put the people yearly in possession of a sum as 
great as the interest of one hundred millions sterling, inde¬ 
pendent of the advantage of speed, and of the great saving 
of tonnage, the rail-road lines being one-third shorter than 
the canals in use. Finally, 1000 persons may be conveyed 
one mile, or one person 1000 miles, by locomotive engines, 
at the rate of eight miles an hour, at a cost of something less 
than five pence. 
Of all the purposes that steam has been applied to, one 
of the most astonishing, though certainly not the most 
useful, is the projection of balls. The steam gun of Mr. 
Perkins was exhibited to the Duke of Wellington and other 
officers, in the year 1825, with the following surprizing re¬ 
sults. At first, the balls were discharged at short intervals, 
in imitation of artillery firing, against an iron target, at the 
distance of thirty-five yards. Such was the force with which 
they were driven, that they were completely shattered to 
atoms. In the next experiment the balls were discharged 
at a frame of wood, and they actually passed through eleven 
one-inch planks of the hardest deal, placed at a distance of 
an inch from each other. Afterwards they were propelled 
against an iron plate one-fourth of an inch thick: at the very 
first trial the ball passed through it. The pressure of steam 
employed to effect this wonderful force did not at first exceed 
65 atmospheres, or 9001bs. to the square inch; and it was 
repeatedly stated by Mr. Perkins, that the pressure might be 
carried 
