The Cecil Whig. [volume] (Elkton, Md.) 1841-current, 1869-02-20
ROAD LOCOMOTIVES.

| pccoHic cAleLSlNclt anu aN OraDlN
known, we find an account of Mr.. r..
w. Thompson's road-steamer. That a
steam-engine, designed to run over
common roads, and even over rough
fields, had been built in Edinburgh,
and had met with certain degree of
success, has been dimly known to most
American readers; but, we think, so
full an account has not heretofore been
published on this side of the Atlantic.
Mr.. Thomson's first successful expert
ments were made with small engine,
after which he built one of eight tons
weight, having vertical boiler, and
standing on two geared driving and
two steering wheels.
The driving tires are made of bands
of vulcanized India-rubber Is inches
wide and inches thick This soft and
elastic substance carries the great
weight of the locomotive without in
jury, over newly broken road-ballast,
broken flints, and all kinds of sharp
things, without even leaving mark
on the 1ndia-rubber. 1t does not sink
into the road in the least degree 1t
hpassed over the stones lying on the sur
face, and even over potatoes and car
rots, purposely laid in its path, with
out crushing them. 1t resembles, in
some degree, the feet of an elcphat.-
AS remarked by Professor Archer, in
his paper before the British Associa-
ton, both the camel and elephant have
very large soft cushions in hard hoofs,
and no other animals can stand so much
walking over hard roads.
The power required to propel the
locomotive is very much less than
would be required if the tires were hard
and rigid. They do not crush nor sink
into the roadway. The machine, as it
were, floats along on the India-rubber,
and all the power used in crushing and
grinding the stones under rigid tires is
entirely saved. 1t might at first sight,
be supposed that it would take great
deal of power to propel heavy car
riage on soft tires; but if the tires are
elastic as well as soft, the power used
in COMPRISING them in front of the
wheel is nearly all given back as the
elastic medium expands behind the
wheel. In fact, the India-rubber tires
require scarcely any more power to
propel them over soft, bad roads, or
over loose gravel roads, than on the
! best paved streets.
"On soft grass-field in which an
ordinary steam-carriage would have
sunk, the rubber tires were run with
out even leaving track On a field
which had just been covered with loose
earth to the depth of one or two
feet, they ran straight across and back,
without difficulty, and compressed the
earth so little that walking-stick
could easily be pushed down in the
track of the wheels.
"When riding on the road-stcamer
the feeling is like what would be ex-
perienced in driving over a smooth
grass lawn. There is absolutely no
jarring. Thus the machinery is spared
the severe trials arising from the blows
and jolts to which it is subjected when
mounted on common wheels
"Therc is, incredible as it may APP
pear, no indication of wear ON the In
dia-rubber tires. The original surface
which the rubber had when it left the
mandatory is still visible
"The tractive powers of the machine
have surpassed all expectation. 1t was
constructed to drag an omnibus, weigh
ing, with its load of say 80 passengers,
about four tons, on level road, but its
capacity is SO greatly in excess of this
task, that no load placed behind it has
fully tested its power. On a road so
slippery from frost that horses had the
greatest difficulty to keep on their legs,
no difficulty was found in going over
the glazed surface by the India-rubber
wheels, with load of Is tons Ga large
boiler on truck on an incline of
in -.
"On one occasion, the locomotive
drew coal train, in all 80 feet long,
consisting of four wagons, weighing,
loaded, 80 tons, 8 miles, over grades of
l in l6.
1.-The steering of the locomotive,
while hauling the coal train in the
crowded streets of Edinburgh, and
around sharp corners, was very sue
cessful. The line of streets through
which it passed is always the most
crowded in the city. but at the time
hetrain passed through these thorough
fares there happened to be an unusually
great current of traffic passing in a
contrary direction to where some games
were going on, which gave rise to
great stream of omnibuscs, cabs, and
conveyances of every description
Notwithstanding all these obstacles,
aggravated by the streets being at some
points under repaia and closed for one
half of their width, no difficulty was
experienced in steering clear of every
impeachment.
1.-THE extremely curious wayin which
the whole four wagons follow, snake
like, in the track of the road-steamer,
was clearly seen in passing out of
North Bridge into Leith street. First,
the road-steamer had to tnrn to the
right, and before the last wagon was
round the corner to the right, the road
steamer had already turned sharp to
| VIC I'LL W SO lulO lIcltu StTtet-IuuS
the train actually assumed the form of
the letter S, every wagon going over
the same ground as the road-steamer
with the most perfect accuracy. The
very steep and crooked decent of Leith-
street, which has a gradient ofprobubly
| in u, was managed with perfect case.
The final maneuvrc was turning with
the whole train out ola street 30 feet
wide into lane 25 feet wide, up a
steep incline 1t passed in at the first
trial, leaving so much space to spare
that it was found, on afterward mea-
surfing the wheel-tracks, a width of
fourteen feet would have sufficed, though
the breadth of the wagon is seven feet.
Gas tousefulness for army purposes,
the Railway News remarks that few
of these engines working up the Col de
Balaclava might have saved many lives
in the Crimean winter of 1854, and the
increased weight of seige ordnance
would now give to an engine of this
sort an Importance which it could not