and in immediate proximity to the Wylam Colliery railway. He was brought up as a colliery engineman, and by his industry and ability had succeeded in improving his position step by step. At the date of the locomotive engine trials above referred to, Stephenson held the position of colliery engineer, or chief enginewright, at Killingworth and other collieries belonging to Lord Ravensworth and partners—a company known by the name of the "Grand Allies." The Killingworth railway was only one or two miles distant from the Kenton and Coxlodge and Heaton railways, and a few miles further from the Wylam railway.

The adoption of steam locomotion on the Killingworth railway having been sanctioned by the owners of the colliery, Stephenson set about the construction of an engine early in 1814.1 Following the design of Blenkinsop's engine, he employed a cylindrical boiler of wrought iron, with an internal wrought iron firetube passing through it; two vertical cylinders of eight inches diameter and two feet stroke let into the boiler, with cross-heads and connecting-rods to work the propelling gear. At this point, however, he took the opportunity to depart from Blenkinsop's plan. The regular working of the smooth-wheeled locomotive on the Wylam railway had shown that, on railways

2

1 Nicholas Wood on Railroads, ed. 1831, p. 134.

2 Smiles's Lives of the Engineers, "George and Robert Stephenson," ed. 1874, p. 82-3.

XVIII.] FEW IMPROVEMENTS FOR MANY YEARS. 225

deviating but little from a dead level, the patent rackrail with its corresponding pinion was not essential.1 Stephenson accordingly decided to make use of smooth wheels.

Stephenson's engine was tried on the Killingworth railway on July 27th, 1814, upon a piece of road with edge-rails ascending about one in four hundred and fifty. It dragged after it, exclusive of its own weight, eight loaded carriages, weighing altogether thirty tons, at the rate of four miles an hour, and after that time continued to work regularly.2

For a considerable number of years few improvements of much note were effected in the locomotive. The spur-gearing, which was employed in Hedley's and Blenkinsop's engines, as well as in Stephenson's first engine, was soon abandoned by the latter for the simpler arrangement of attaching the connectingrods directly to the driving-wheels an improvement which was patented by Dodds and Stephenson on the 28th of February, 18153 (Fig. 45). Springs too were applied by Stephenson at the suggestion of Mr. Nicholas Wood. But even as late as the year 1827 the fate of the locomotive engine still hung in the

4

1 Nicholas Wood on Railroads, ed. 1831, pp. 129, 132, 133.
2 Ibid., ed. 1831, p. 136.
3 No. 3887.

4 In 1816, Stephenson, in conjunction with Mr. Losh, patented an arrangement of steam piston springs, but this being found open to numerous objections, was soon abandoned in favour of steel springs.

૨

balance. Of five locomotives supplied by Stephenson, in 1822, to work on the Hetton Colliery railway, three had been laid aside in favour of fixed engines; and in a Report on the colliery made in 1827, it was recom

mended as

well worthy of consideration whether it would not be advisable to substitute reciprocating engines" in place of the two remaining locomotives.1 On the Stockton and Darlington railway locomotives

These two locomotives drew sixteen waggons each, and worked a portion of the railway one and a quarter miles in length.

XVIII.]

TIMOTHY HACKWORTH.

227

continued to be used, but "the principal haulage of the line was performed by horses." The working of the locomotive engines appears not to have been regarded with any degree of satisfaction, and it is stated to have been under consideration in 1827, whether horses should not be alone employed, to the exclusion of locomotive engines.' As yet locomotion by steam had not achieved much success; an efficient form of engine remained to be invented.2

At this juncture, Timothy Hack worth, a highly ingenious mechanic, who occupied the position of manager of the working department of the Stockton and Darlington railway, introduced some important modifications in an engine which he designed, whereby the power and compactness of the smooth-wheeled locomotive were much advanced.3 Departing from the then usual plan of having two upright cylinders working on different shafts, Hackworth inverted his cylinders, and,

1 History of the Steam Engine, by Robert Scott Burn, 2nd ed. p. 114. 2 At this period the locomotive engine was as unpopular in the North of England as it was inefficient. In the Act of Parliament for making the Newcastle and Carlisle railway, which received the Royal Assent on May 22nd, 1829, it was expressly provided that " no locomotive or moveable steam engine shall be used on the railway for drawing waggons or other carriages, or for any other purpose whatsoever."

3 The boiler of the engine was taken from a locomotive which had been supplied to the Stockton and Darlington railway by Wilson of Newcastle-on-Tyne. As originally constructed it had four cylinders, two to each pair of wheels, and appears to have been the first engine in which the power from two pistons was applied to a single pair

placing them on opposite sides of the boiler, applied their connecting-rods to actuate the same axle-tree. At the same time he adopted the return fire-tube which was used by Trevithick and Hedley, in lieu of the straight flue employed in Blenkinsop's and Stephenson's engines; and by throwing the escaping steam into the chimney through a narrow orifice, he greatly augmented the force of the steam-blast, and consequently the rapidity of combustion in the furnace.1

The engine in which the above improved arrangements were first combined was built by Hackworth in 1827, and named the "Royal George" (Fig. 46). It was the first of a new type, and the nearest approach to

of wheels. [Zerah Colburn on Locomotive Engineering, &c., p. 21.] How the four cylinders were placed we are not informed, but it is obvious that the arrangement was inefficient, from the fact of its being so soon abandoned.

1 Hackworth was a native of Wylam, and took part in the building of "Puffing Billy." He was one of the most ingenious of the pioneers of locomotive engineering. [For an account of him, see The Practical Mechanic's Journal, Vol. III., p. 49, 1850-51-"A chapter in the History of Railway Locomotion,” and memoir, p. 225 of same volume.]

There has been considerable controversy regarding the invention of the steam-blast which is so essential a feature of the locomotive engine. The improved combustion arising from turning the waste steam into the chimney was well known to Trevithick and Mr. Davies Gilbert, the latter having written a letter on the subject to Nicholson's Journal in 1805. We have the testimony of Mr. Nicholas Wood, however, that "it was afterwards laid aside or only partially used, when only slow rates of speed were required," until revived by Mr. Hackworth, "in a more forcible manner than before used, throwing it up as a jet," &c. [Treatise on Railroads, ed. 1831, p. 390.]