The locomotive needed something more, some magic touch to render it less clumsy and more effective. What was it?
Then came the first great practicable improvement after the smooth wheels on smooth rails. It was the steam-blast in the funnel, by which the draught in the furnace was greatly increased. Indeed, the faster the engine ran the more furiously the fire would burn, the more rapid would be the production of steam, and the greater the power of the engine.
At first Stephenson had allowed his waste steam from the cylinders to blow off into the air. So great was the nuisance caused by this arrangement that a law-suit was threatened if it were not abated.
What was to be done with that troublesome waste steam? Now, whether Stephenson originated the idea or adapted what Trevithick had done, we cannot say, but at all events he achieved the object, wherever he gained the idea. He turned his exhaust steam through a pipe into the funnel, and at a stroke increased the power of his engine two-fold.
But that expedient was not alone. Stephenson had watched the working of “Blucher” to some purpose, and he decided to build another engine with improvements.
The cumbersome cog-wheels must go; they complicated the machine terribly, and prevented its practicability. Therefore in his second engine he introduced direct connection between the pistons and the wheels. There were a couple of upright cylinders as before, with cross-rods attached to the piston-ends, and connecting rods from the end of each cross-rod, reaching down to the wheels. But to overcome the difficulty of one wheel being at some time higher than the other on the poorly constructed railway of that period, a joint was introduced in the cross-rod, so that if, perchance, the two wheels should not be always on exactly the same level, no undue strain should be placed on the cross-rod. Furthermore, the two pairs of wheels were combined first by a chain, but afterwards by connecting rods. This may be called the locomotive of 1815, the year in which the patent was taken out.
EDWARD PEASE.
The engine accomplished its work more satisfactorily than before, and was placed daily on the rails to haul coal from the mine to the shipping point. But still its economy over horse-power was not so great as to cause its wide adoption. And it was still little better, if anything, than a mere coal haul.
Nevertheless Stephenson persevered. He was appointed engineer to the Stockton and Darlington Railway—an enterprise largely promoted by Mr. Edward Pease. It was opened on the 27th of September, 1825, and a local paper writes as follows:—