The Elk County advocate. [volume] (Ridgway, Pa.) 1868-1883, 1872-06-13
A Marvellous Machine.

Mr.. Thompson, o well-known Edin-
burgh civil engineer, has for many years
paid special attention to the properties
and capabilities of india-rubber. He
was the first, some twenty years ago, to
apply tires of this Substance to the
wheels of trucks, ETC., at railway stations
in order to deaden the sound; and to
him we are also indebted for the more
recent discovery that india-rubber, when
in q great mass, fattens on a road or
floor, and, by presenting greater ex-
tent of bearing surface, causes any SUI
perincumbent weight to be distributed
over a much larger area. Hence he con-
ceived and carried out the idea of pro-
viding the wheels of a steam-engine, to
run on common roads, with india rubber
tires of an immense thickness. In con-
sequence of the soft, elastic property of
such tires, the wheel-surface may, ac-
cording 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 web
footed effect of the aquatic animal when
walking on the morass."
When the first patent road-steamer
was tried, some three years ago, its sue
cess was complete, and far exceeded Mr..
Thompson's. expectations. In the be-
ginning of 1870, the War Department
having heard Of some of its performances,
commissioned Mr.. Anderson to proceed
to Edinburgh and examine it personally,
and to report upon its capabilities for
military purposes of various kinds; and
it is from this report, dated the 8th Of
April, 1870, and signed conformity by
Mr.. Anderson and Mr.. Bailey, Assistant
Controller, that we have obtained most
of our information regarding this mar
velous machine.
The wheels of this 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 q smaller wheel in
front, which is for steering purposes, and
is so completely under control as to
answer the slightest touch OF the hand
Each wheel has broad iron tire, with
narrow Hanges, upon which is placed q
soft vulcanized india-rubber ring, about
twelve inches in width and five in thick
ness, the hanges keeping it in its place
Over the india-rubber there is placed an
erdless chain of steel plates, three-and-
a-half inches wide, which form the por-
ton of the wheel that comes in contact
with the rough road and this reticulat-
ed chain is connected with what may be
called vertebra at each side of the wheel
Tho india-rubber tire and the ringed
steel plates have no rigid connection,
and arc at perfect liberty to move
round Independently Of each other, or
even without the concurrence of the in
ner ring of the wheel which they both
inclose. This remarkable combination
contributes materially to the great sue
cess Of the wheel. Small tubes are per-
forated in the tire of the wheel, to admit
the atmosphere under the india-rubber
ring. Without such holes, it was found
that "the weight of the load was suffi-
cient to exclude the atmosphere, so that
one side of the india-rubber would thus
be made to adhere to the iron with the
atmosphere pressure, while the other
side would have to stretch and bag out
ward" An ordinary wheel, if it is a
rigid structure, presents to the road only
small surface but this wheel conforms
to every irregularity for space of nearly
two feet, by the weight of the engine
causing the india-rubber to collapse, and
thus producing SO great change oi
| form.