The Columbia herald. [volume] (Columbia, Tenn.) 1850-1873, 1872-02-16
A Marvellous Machine.

Mr.. Thomas, q -well-known Edin.
burg civil engineer, has for many
years paid special attention to the
properties and capabilities OF India
rubber. He was the Rsrt, some twenty
years ago, to apply tires of this sub
stance to the wheels of trucks, &c.
at railway stations, in order to deaden
the sound; and to him we are in
debted for the more recent discovery
that India-rubber, when in agreat
mass, fattens on road or floor, and,
by presenting a greater extent of
bearing surface, causes any superin-
cumbent weight to to distributed over
much larger area. Hence he conceived
and carried out the idea of providing
the wheels of q steam engine, to run
on common roads, with Idia rubber
tires of immense thickness. In con.
sequence of the soft, elastic property
of such tires, the wheel surface may,
according to the condition of the
road over which it passes, "present
the broad, quiet tramp of the foot
of the elephant, the gentle step of the
feline race, or the webfooted effect of
the aquatic animal when walking on
the morass."
When the first patent road-steamer
was tried, some three years ago, Its
success was complete, and far exceeded
Mr.. ThOmson's expectations. Iu the
beginning of 1870, the War Depart
ment. having heard of some of its
Performances, commissioned Mr.
Anderson to proceed to Edinburg to
examine it personally, and to re-
port upon its capabilities for military
purposes of various kinds; and il is
from this report, dated the Sth of
April, 1870, and from a second report
dated the l4th of May, 1870, and
signed ccnjcintIy by Mr.. Anderson
and Mr.. Baily, Assistant Comptroller,
that we have obtained most of our
information regarding this marvellous
machine.
The wheels of the road-steamer are
three in number-namely, two driving
wheels, about five feet in diameter,
on which almost the whole weight of
the engine rests; and smaller wheel
in front, which is for steering purposes.
and is SO completely under control rs
to answer the slightest touch of the
hand. Each wheel.hasia broad iron tire,
with narrow flanges, upon which is
placed soft vulcanized India-rubber
ring, about twelve inches in width aud
five in thickness, the f1anges keeping
it in its place. Over the India.rubber
there is placed an endless chain Of
steel plates, three and a half inches
wide, which form the portion Of the
wheel that comes In contact with the
rough road; and this reticula-
ted chain is connected with what may
be called vertebre at each side of the
wheel. ..j ....
The ,India-rubber tire and the
ringed steel plates have no rigid con-
.nection, and are at perfect liberty to
move round independent Of each
other, or even without the concurrence
of the inner ring of the wheel which
they inclose. This remarkable COM
bination contributes materially to the
great success Of the wheel. Small
tubes are perforated In the irHn tire If
the wheel, to admit the atmosphere
under the India-rubber ring. Without
such holes, it was found that "the
weight Of the load was sufficient to
exclude the atmosphere, so that one
side of the India-rubber would thEs
he made to adhere to the iron with the
full atmospheric pressure, while the
other side would have to stretch and
bag outward"