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Mr. Walker, in his report, assumed that the power of the
engine was in an inverse ratio to its velocity; but Mr.
Stephenson held, what has since been clearly established,
that, instead of the steam becoming exhausted, and the
working power of the locomotive lessened, in proportion to
its speed, the result was the very reverse, and that the
expenditure of steam was, by means of the important con-
trivance of the blast, made subservient, through the more
intense combustion of fuel which it excited, to the increased
production of power in the engine.*

This principle was afterwards clearly illustrated by Mr. Robert Stephenson
in the joint essay entitled "Observations on the Comparative Merits of Locomo-
tive and Fixed Engines," published by himself and Mr. Locke (as compiled
from the Reports of Mr. George Stephenson) in reply to the Report of Mr. James
Walker, C. E. The pamphlet was published in February, 1830.

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"In locomotive engines hitherto constructed, the area of the surface in the boiler acted upon by the fire is much less than that generally employed in stationary engines; and hence it is that the consumption has been much greater to produce equal effects. This inconvenience has been submitted to, in order that simplicity and compactness might be achieved.

"To compensate for the loss of heating surface, it was necessary to augment the temperature of the fire. This was effected shortly after the first locomotive engine was tried on the Killingworth Colliery Railway, by conveying the steam into the chimney, where it escaped in a perpendicular direction up the centre, after it had performed its office in the cylinders. The velocity of the steam on entering the chimney being much greater than that due to the ascending current of air from the natural draft of the furnace, the effect was to increase the draught, and consequently the temperature of the fire. . . . Since it has been shown that the power of these engines, under similar circumstances, is chiefly dependent on the quantity of fuel consumed, it is evident that, by this application of the waste steam to accelerate combustion, the power of the engine actually varies under different velocities. This curious fact, connected with the construction of locomotive engines on the principle of the Rocket,' has not hitherto, we believe, been represented in this manner; and it is so important, that any calculation neglecting its consideration, at high velocities, must be regarded as futile and absolutely false.

"Mr. Walker takes the power of a locomotive engine, of the size and construction of those used upon the Darlington Railway, equal to 10 horses, at

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CHAP. XXI.] PRIZE FOR THE BEST LOCOMOTIVE.

277.

The directors could not fail to have been influenced by these arguments. But the fixed-engine party was very strong at the board, and, led by Mr. James Cropper, they urged the propriety of forthwith adopting the report of Messrs. Walker and Rastrick. Mr. Sandars and Mr. William Rathbone, on the other hand, desired that a fair trial should be given to the locomotive; and they with reason objected to the expenditure of the large capital necessary to construct the proposed engine-houses, with their fixed engines, ropes, and machinery, until they had tested the powers of the locomotive, as recommended by their own engineer. Mr. Stephenson continued to urge upon them that the locomotive was yet capable of great improvements, if proper inducements were held out to inventors and machinists to make them; and he pledged himself that, if time were given him, he would construct an engine that should satisfy their requirements, and prove itself capable of working heavy loads along the railway with speed, regularity, and safety.

The directors were more bewildered than ever. Yet they had confidence in their engineer, and had but recently borne public testimony to his practical efficiency. They had seen him form a road which other engineers of high reputation had repeatedly declared to be impracticable; and it might be the same with the locomotive.

At length, influenced by his persistent earnestness not less than by his arguments, the directors, at the suggestion of Mr. Harrison, determined to offer a prize of 500l. for the best locomotive engine, which, on a certain day, should be

2 miles an hour. Presuming that the effect is inversely as the velocities, he reduces the power of the engine at 10 miles an hour, to 24 horses' power, or =375 lbs. This conclusion would have been perfectly correct if the quantity of steam generated in the boiler in equal times were the same at all velocities; but the fallacy of this assumption, in reference to locomotive engines, has been sufficiently explained in the foregoing remarks."- Observations, &c., pp. 6–8.

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produced on the railway, and perform certain specified conditions in the most satisfactory manner. The conditions were these

1. The engine must effectually consume its own smoke.

2. The engine, if of six tons weight, must be able to draw after it, day by day, twenty tons weight (including the tender and water-tank) at ten miles an hour, with a pressure of steam on the boiler not exceeding fifty pounds to the square inch.

3. The boiler must have two safety valves, neither of which must be fastened down, and one of them be completely out of the control of the engineman.

4. The engine and boiler must be supported on springs, and rest on six wheels, the height of the whole not exceeding fifteen feet to the top of the chimney.

5. The engine, with water, must not weigh more than six tons; but an engine of less weight would be preferred on its drawing a proportionate load behind it; if of only four and a half tons, then it might be put on only four wheels. The Company to be at liberty to test the boiler, &c., by a pressure of one hundred and fifty pounds to the square inch.

6. A mercurial gauge must be affixed to the machine, showing the steam pressure above forty-five pounds per square inch.

7. The engine must be delivered, complete and ready for trial, at the Liverpool end of the railway, not later than the 1st of October, 1829.

8. The price of the engine must not exceed 5501.

It will be observed that the requirements of the directors as to speed were not excessive. All that they asked for was, that a speed of ten miles an hour should be maintained. Perhaps they had in mind the severe animadversions of the Quarterly Reviewer on the absurdity of travelling at a greater velocity, and also the remarks published by Mr. Nicholas Wood, whom they selected to be one of the

CHAP. XXI.]

SUSPENSION OF PUBLIC OPINION.

279

judges of the competition, in conjunction with Mr. Rastrick of Stourbridge and Mr. Kennedy of Manchester.*

It was now generally felt that the fate of railways in a great measure depended upon the issue of this appeal to the mechanical genius of England. When the advertisement of the prize for the best locomotive was published, scientific men began more particularly to direct their attention to the new power which was thus struggling into existence. In the meantime public opinion on the subject of railway working remained suspended, and the progress of the undertaking was watched with the most intense interest.

* Many persons of influence declared the conditions published by the directors of the railway chimerical in the extreme. One gentleman of some eminence in Liverpool, Mr. P. Ewart, who afterwards filled the office of government inspector of Post Office steam-packets, declared that only a parcel of charlatans would ever have issued such a set of conditions; that it had been proved to be impossible to make a locomotive engine go at ten miles an hour; but if it ever was done, he would eat a stewed engine-wheel to his breakfast!

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We now return to the history of the locomotive factory commenced by Mr. Stephenson and his associates at Newcastle in the year 1824. Its establishment at that early period was a most important step in the progress of the railway system, and mainly contributed to the eventual triumph of the locomotive. Mr. Stephenson engaged skilled mechanics in the workshops, by whose example others were trained and educated. Having their attention specially directed to the fabrication of locomotives, they acquired a skill and precision in the manufacture of the several parts, which gave to the Stephenson factory a prestige which was afterwards a source of no small profit to its founders. It was

a school or college, in which the locomotive workmen of the kingdom were trained; and many of the most celebrated engineers of Europe, America, and India, acquired their best practical knowledge in its workshops.

Several years, however, passed before the factory so much as paid expenses. For the first four or five years it was carried on at considerable loss; and Edward Pease wished to retire, but Mr. Stephenson could not provide the necessary money to buy him out. It must therefore be persevered in until the locomotive had established itself in public estimation as a practicable and economical motive power. And that time was now fast approaching.

It will be remembered that Robert Stephenson set out for the mines of Columbia in South America in the year 1824, during the time that the works of the Stockton and Darlington

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