254 BIOGRAPHICAL NOTICES. 
four miles, in waggons drawn by horses along a railroad, and Mr. 
Blenkinsop, seeing the failure of Trevi thick's efforts, and having a 
place so suitable at command, began to make experiments on his own 
account. On the 10th of April, 1811, he obtained a patent for 
certain mechanical means, by which the conveyance of coal, minerals, 
and other articles, is facilitated, and the expense is rendered less than 
heretofore. An engine was built for him by Messrs. Fenton, Murray, 
and Wood, of Leeds. Following the presumed necessity for a more 
effectual adhesion between the wheels and the rails than that presented 
by their mere smooth contact, Mr. Blenkinsop's patent provided a 
racked or toothed rail, laid along one side of the road, into which 
the toothed wheel of his locomotive worked, as pinions worked into 
a rack. The boiler of his engine was supported by a carriage with 
four wheels, without teeth, and rested immediately on the axles. 
These wheels were entirely independent of the working parts of the 
engine, and therefore merely supported its weight on the rails, the 
progress being effected by means of the cogged wheel working into 
the cogged rail. The engine was provided with two double-acting 
cylinders, instead of one as in Trevithick's engine. By this con- 
trivance the fly-wheel was rendered unnecessary, and uniformity of 
action was secured. The invention of the double cylinder was due 
to Matthew Murray, of Leeds, one of the best mechanical engineers 
of his time, Mr. Blenkinsop (who was not himself a mechanic), having 
consulted him as to all the practical arrangements of his locomotive. 
The cylinders were placed vertically, and were immersed for a con- 
siderable portion of their length in the steam space of the boiler. 
The boiler was of cast-iron, of the plain cylindrical kind, with one flue, 
the fire being at one end and the chimney at the other. The connecting 
rods gave the motion to two pinions by cranks at right angles to each 
other. The pinions communicated the motion to the wheel, which 
worked into the toothed rail. Mr. Blenkinsop's engine began 
running on the railway extending from the Middleton Collieries to 
Leeds on the 12th of August, 1812. They continued for many years 
to be the principal curiosities in the neighbourhood, and were visited 
by strangers from all parts. The locomotive did the work of sixteen 
horses, and drew twenty-seven waggons, weighing ninety-four tons. 
