October 6, 1892] 



NATURE 



539 



shaft carried a heavy flywheel, and was connected to the 

 carrying wheels of the engine by means of spur gearing. 

 The exhaust steam was discharged into the chimney, 

 ■ensuring an efficient supply of steam. 



In the year 1808 Trevithick laid down a circular rail- 

 way in a field which now forms the southern half of Euston 

 Square. The locomotive exhibited had a vertical cylinder, 

 the crosshead being coupled direct to the hind pair of 

 wheels. This engine weighed about ten tons, and ran 

 at an approximate speed of ten to twelve miles per 

 hour. From these data it will be at once seen that 

 Trevithick was before either Hedley or Stephenson 

 with the invention of the locomotive engine, since both 

 Hedley's and Stephenson's experiments date from the 

 year 181 3. 



The volume under notice is full of historical data hav- 

 ing reference to these early experiments. The author 

 has taken great pains in arranging the matter. Further 

 on in the book, chapter iii., another most interesting sub- 

 ject is dealt with. " The Battle of the Gauges " will long 

 be remembered by engineers. The standard gauge of 

 railways in this country is 4 feet 8^ inches, measured be- 

 tween the heads of the rails. This peculiar dimension 

 appears to have been originally due to the tramways m 

 use at the collieries where the original experiments were 

 carried out by Stephenson and others, and was adopted 

 for the railways when first projected and locomotives 

 used. The great exception to this standard was the 

 seven-feet gauge of the Great Western Railway. This 

 railway, when projected by Mr. Brunei, was intended 

 to eclipse the narrow-gauge of railways, both in speed 

 and comfort when travelling. This competition, how- 

 ever, is claimed by the author as having been the means 

 of hastening the growth and perfecting the locomotive. 

 Looking at the question from the present day, the 4 feet 

 8^ inch, or standard gauge, is certainly too narrow ; the 

 power of the locomotive has gradually been increasing 

 since Stephenson's day, and a point will soon be reached 

 when radical changes must be made in locomotive de- 

 sign, in order to increase the power still more. On the 

 other hand, the now obsolete seven-feet gauge of Brunei 

 was too large. The Indian engineers have adopted the 

 gauge of 5 feet 6 inches for the standard of that country. 

 This dimension appears to be a " happy mean," and one 

 with which locomotive engineers may revel in large 

 journals and free steam and exhaust ports in locomotives 

 fitted with inside cylinders. 



It is amusing to read that American engines commenced 

 their competition with the English engine in the year 

 1840, when some were imported to work the trains up 

 the Lickey incline of one in thirty-seven on the Birmingham 

 and Gloucester Railway. These engines were made by 

 Messrs. Norrisand Co., of Philadelphia, weighing slightly 

 under eleven tons. The author tells us they thoroughly 

 beat the English engine of that day doing this particular 

 service. 



Every locomotive engineer knows what the Stephenson 

 link motion is — the apprentice in his first year generally 

 prides himself on having mastered its details ; yet, for 

 all this, the author tells us to call this old friend by another 

 name ! It seems that this gear is really due to Mr. 

 William Howe, an employ^ of Messrs. R. Stephenson 

 NO. 1197, VOL. 46] 



and Co., and was adopted by them and first fitted to an 

 engine for the North Midland Railway in the year 1842. 

 It may here be noted that the question of valve gear 

 generally is not sufficiently described or illustrated in this 

 volume. The index contains several references, but these 

 are very superficial. This becomes all the more apparent 

 when the Joy valve gear is fully described and illustrated, 

 besides a diagram showing results of working. 



The Joy valve gear is in the opinion of many an un- 

 suitable gear for a locomotive. It must be evident that 

 any gear which derives its valve motions principally from 

 the vertical movements of the connecting-rod cannot give 

 a good distribution of steam, for the reason that the 

 vertical movements of the connecting rod are affected 

 by those of the driving-axle. The driving-axle is not 

 always in the same position as regards the frames and 

 cylinders owing to the undulations of the road, the 

 oscillation of the engine, and the varying condition of the 

 springs ; a movement of half-an-inch above and below 

 the normal position of the driving-axle is quite within the 

 limits of actual practice. This movement is sufficient to 

 affect the true movement of the valve ; indeed, it is 

 enough to destroy the lead either on the front or back 

 ports as the case may be. Besides this objection, the 

 Joy gear has nominally a uniform lead for all degrees of 

 expansion, whereas it is usually considered necessary to 

 increase the lead for higher grades of expansion and speed 

 of engine. Some locomotive engineers are willing to risk 

 this defective steam distribution in order to take advan- 

 tage of the undoubted improvements in design the adop- 

 tion of this valve gear allows. These mainly consist in 

 the increase in length of the driving-axle bearings for 

 engines with inside cylinders, there being no eccentrics 

 to find room for between the crank webs. The cylinders 

 can be consequently placed closer together, and the steam 

 chest arranged either above or below the cylinders, as the 

 case may be, without the use of rocking shafts or 

 intermediate gear. 



Chapter IV. deals with modern locomotives for main 

 line trains. Many well-known engines are illustrated and 

 described, and we naturally find the Compound Loco- 

 motives of Messrs. Worsdell and Webb included in the 

 number. The author evidently is not enamoured with the 

 compound locomotive, saying that "facts" are in 

 favour of the simple engine. It is here to be noted that 

 no locomotive superintendent in this country, excepting 

 the patentees of the respective systems, has adopted the 

 compound system. What this is due to is uncertain, 

 because the two-cylinder type of compound locomotive 

 known as the Worsdell system has certainly given good 

 results in India and other countries, comparing favourably 

 with the simple engine. The "Gladstone" locomotive, 

 designed by the late Mr. William Stroudley, is among 

 those illustrated. This raises the interesting question as 

 to the wisdom of using large leading coupled wheels for 

 express work ; many engineers prefer a bogie in front, 

 deeming it safer. But when the London and South 

 Western Railway practically copy Mr. Stroudley's arrange- 

 ment of wheels in their latest engines for mixed traffic, 

 one is apt to be surprised at the change coming from the 

 " bogie " head quarters, and to surmise that anything 

 will do. There is, however, nothing new in the adoption 



