882 
write those often quoted lines in the Botanic Garden 
(canto i. line 290) :— 
“ Soon shall thine arm, uneonquered Steam, afar 
Drag the slow barge, or drive the rapid car.” 
(385.) A somewhat longer pause now occurs. But in 
Trevithick 1802 we find Richard Trevithick, a Cornish ‘ cap- 
cone cir tain ” of a mine, taking out a patent along with Vi- 
patent in Vian for the high-pressure steam-engine, and apply- 
1802. ing it specifically and practically to the movement 
of carriages or waggons along a railway at Merthyr 
Tydvil in South Wales. Mr Muirhead informs us 
that Trevithick saw Murdoch’s model at Redruth in 
Cornwall. But admitting this, it is plain that the 
idea was much older still, and also that many years 
elapsed without its ever being brought practically 
to bear until the year 1804, when Trevithick’s loco- 
motive was actually used. 
(386.) Ricuarp TrevirHick appears to have been one of 
Account of the most ingenious men of his time; but (from the 
Trevithick. seanty notices which I have been able to collect) to 
have been also of an inconstant speculative disposi- 
tion, which prevented him from bringing any of his 
numerous inventions to perfection. Yet he had the 
good fortune, which so many inventors have missed, 
of meeting with partners able and willing to assist him 
in carrying out his designs. Amongst these was 
Andrew Vivian, with whom in 1802 he took out the 
patent already mentioned for the construction of high- 
pressure engines, and their application to the move- 
ment of carriages along rails or common roads. As 
: the first practical employer of high-pressure steam of 
seta sig 60 to 80 Ib. pressure on the square inch, Trevithick 
to locomo- deserves especial notice. He borrowed the notion of 
tiveson —_ it, as well as the ingenious invention of the four-way 
oti sin cock, from an old scheme of Leupold’s, but he over- 
- came for the time the prejudice which had always 
existed even in the mind of Watt against its adop- 
tion. His earliest engine is stated to have been con- 
nected with a common stage coach which ran on the 
streets of London ; but his more successful and im- 
portant effort was made in dragging waggons along 
the Merthyr Tydvil railway in South Wales, which 
was successfully tried on the 21st February 1804, 
when the engine drew carriages containing ten tons 
of bar iron for a distance of nine miles at the rate of 
five miles an hour. This was unquestionably the 
first successful example of this modern species of 
locomotion. 
Applies 
" (387.) ; If we look more closely at the means by which it 
bis oudine was accomplished, we find still more reason to com- 
mend the sagacity of the inventor. and to wonder at 
the interval of nearly thirty years which elapsed be- 
fore the general adoption of his plan. “ A square 
iron case containing the boiler and cylinder was placed 
behind the large or hinder wheels of the carriage, and 
was attached to a frame supported from the axles of 
MATHEMATICAL AND PHYSICAL SCIENCE. 
(Diss. VI. 
those wheels. The cylinder was in a horizontal po- 
sition, and the piston-rod was projected backwards 
and forwards in the line of the road towards the front 
of the carriage. Across the square frame, supported 
by the wheels of the carriage, an axle was extended 
reaching a little beyond the frame on each side; this 
axle was cranked in the middle, in a line with the 
centre of the cylinder, and a connecting-rod passing 
from the end of the piston turned this axle round, 
and produced a continued rotatory motion of it when 
the piston was moved backwards and forwards in the 
cylinder; upon both ends of this axle eog-wheels 
were fixed, which worked into similar cog-wheels 
upon the axles of the wheels of the carriages, so that 
when a rotatory motion was produced in the cranked 
axle by the piston-rod it was communicated to the 
axle of the larger or hinder wheels of the carriages, 
and these wheels being fixed upon and turning round 
with the axle, gave a progessive motion to the car- 
riage. Upon one end of the axle was fixed a fly- 
wheel to secure a rotatory motion in the axle at the 
termination of each stroke.” * 
We here find the cranked axle and the horizontal 
eylinder of modern locomotives, both of which were 
departed from by Trevithick himself, probably in 
consequence of difficulties of exeeution. When we 
add to this plain description, that the fly-wheel was 
furnished with a break, that the boiler had a safety- 
valve or a fusible plug beyond the reach of the engi- ‘ 
neer, and that the patent includes the production of 
“a more equable rotatory motion, .«. . . by caus- 
ing the piston-rods of two cylinders to work on the 
said axis by means of cranks at a quarter of a turn 
asunder,” it is scarcely too much to say that nothing 
material was added to the design of the Locomotive 
until the invention of the tubular boiler in 1829. 
The Merthyr locomotive blew up, and the preju- 
dice against high-pressure steam revived. The in- Trevi. 
ventor, in the meantime, diverted his attention to peer 
other schemes, and continued his profession as a plodes. 
Cornish mining engineer. 
A singular circumstance opened for Trevithick a 390.) 
new sphere. A Spanish-American gentleman named His subse- 
Uvillé, who was engaged in working the silver mines eieard 
of Peru, came to England in 1811, with a view to disappoint- 
discover an engine fit for draining those mines whose ment. 
high elevation rendered condensing steam-engines 
working under atmospheric pressure comparatively 
inert.. In London he met accidentally with a model 
of Trevithick’s engine, and haying carried it to the 
heights of Pasco in Peru, and being satisfied with its 
work, he did not rest until he had returned to Eng- 
land and transported nine high-pressure engines in 
1814 to the scene of operations. in 1816 Trevi- 
thick himself followed, with coining engines and pu- 
rifying furnaces of his own contrivance. Had he 
(388.) 
(389.) 
Trevi- 
1 It is stated that the Society of Civil Engineers have in vain proposed a medal for a biography of Trevithick. 
2 Wood on Railways. 
cond Series, vol, iv. 
This description corresponds with Trevithick’s specification and drawings.—Repertory of Arts, &c., Se- 
“ 
