August 9, 1883] 



NATURE 



357 



be accurate when forced beyond a certain rate, does not hold 

 good of mechanical processes. Generally it may be said that 

 rapidity of working not only reduces cost but improves the 

 result, and also confers great benefits from the way in which it 

 brings out and perfects the highest qualities of the engineer. 

 Td be able to do a thing leisurely and quietly simply re- 

 quires the rudest materials and the rudest workmanship ; but 

 if work is to be done quickly, or the appliances made to 

 move quickly, the case alters. Mechanical energy increases 

 as the square of the speed ; and so it may be said that the 

 mental energy and skill required to carry on work increase also 

 at something like the square of the speed with which that work 

 is performed. The materials used must be far stronger and far 

 finer ; everything must be well proportioned and balanced ; there 

 must be the most perfect arrangement in each structure and in 

 every part of a structure, and the most perfect workmanship in the 

 fitting of those parts together ; and thus we may almost reverse . 

 the proverb, and say of mechanical processes, ' The higher the 

 speed, the better the work.' 



"The torpedo boat is an excellent example of the advance 

 towards high speeds, and shows what can be accomplished by 

 studying lightness and strength in combination. In running at 

 22J knots an hour, an engine with cylinders of 16-inch stroke 

 will make 480 revolutions per minute, which gives 12S0 feet per 

 minute for piston speed ; and it is remarked that engines running 

 at that high rate work much more smooihly than at slower speeds, 

 and that the difficulty of lubrication diminishes as the speed 

 increases : doubtless the experiments on friction which are now 

 being conducted by this Institution will throw light upon this 

 subject. 



' ' An important experiment on high speed in light vessels, which 

 will doubtless be watched with much interest, is now being 

 carried out. Mr. Loftus Perkins is building a steel vessel with a 

 screw at each end : she is 150 feet long ; her boiler pressure will 

 be about 800 lbs. per square inch, and she has a four-cylinder 

 compound condensing engine of Soo h.p. working on to a single 

 crank, and making from 400 to 500 revolutions per minute. 

 When this vessel is laden with 300 passengers, her total weight 

 will not much exceed 150 tons. Should this experiment be 

 successful, it will materially advance the solution of the problem, 

 how to put the largest possible amount of propelling power into 

 a vessel, and so to drive her at the highest possible speed. 



"Again, in touching upon speeds, the mind naturally reverts 

 to railway travelling. Here, however, it would seem as if for 

 the present we had reached a maximum. It is surprising how 

 soon the speed of the locomotive was brought up to something 

 approaching its present limit. George Stephenson was laughed 

 at in 1S25 for maintaining that trains would be drawn by a loco- 

 motive at twelve miles an hour, but the ' Rocket ' herself attained 

 a speed of twenty-nine miles an hour at the Rainhill competition 

 in 1829, and long afterwards ran four miles in four and a half 

 minutes. In 1834 the average speed of trains on the Liverpool 

 and Manchester Railway was twenty miles an hour ; in 1S38 it 

 was twenty-five miles an hour. But by 1S40 there were engines 

 on the Great Western Railway capable of running fifty miles an 

 hour with a train and eighty miles an hour without. In 1841 we 

 find Stephenson himself ranged on the side of caution, and 

 suggesting that forty miles an hour should be the highest regular 

 speed for trains. In 1851 Mr. Crampton, who had already in 

 1849 inaugurated the express service of the Continent on the 

 Northern Railway of France, conveyed a train twenty miles in 

 nineteen minutes, four miles in the journey being at the rate of 

 seventy-five miles an hour. Thus, it is a remarkable fact that 

 the highest speed at which locomotives run in ordinary practice 

 scarcely seems to have been raised during the last thirty years ; 

 on the other hand, the weight of the trains has been perhaps 

 doubled. 



" What are the causes which have tended to prevent any im- 

 provement in this particular ? In the first place it may be said 

 that the permanent way would suffer seriously by further increase 

 in speed ; but this could surely be overcome in time by improving 

 the permanent way itself, which also remains very much in the 

 same condition and of the same construction as it was twenty-five 

 years ago. Again, it may be said that the running at a higher 

 speed would require more powerful engines, and hence that 

 trains now worked by a single engine would require two, or 

 would have to be split up into two trains at a great increase in 

 running expenses. This, however, assumes that it is not 

 possible so to improve the engine that it shall be able to exert a 

 considerably higher power without an inadmissible increase in 



weight. By utilising a larger part of the total weight of the 

 engine as adhesion weight it would be easy to obtain the amount 

 of adhesion required for the increased tractive force ; and for 

 this purpose Mr. Webb's compound locomotive (to be described 

 by the author in a paper he has prepared for this meeting) 

 which enables the number of driving wheels to be increased 

 without the use of coupling-rods, appears to merit particular 

 attention. 



"Another point in which improvement may possibly arise in 

 the future should be noticed. On the Russian railways, where 

 both coal and wood are dear, the burning of petroleum has now 

 taken a practical form. Our member, Mr. Thomas Urquhart, 

 has been very successful in this direction, and is now running 

 locomotives regularly which use only petroleum refuse, and 

 which show a marked economy over coal or wood. To test the 

 point he prepared three locomotives of exactly the same type, 

 and started them on successive days under exactly similar condi- 

 tions of weather, train, and section of road. The trips were 

 made both ways, and the results per verst, including fuel required 

 in lighting up, were as follows : — 



Copecks. 



Anthracite, 52-9 Russian lbs., cost 2°'35 



Wood, o'oio7 cubic sashin, cost 2 3'54 



Petroleum refuse, 27 36 Russian lbs. , cost ... 1 1 04 



" There is thus in this instance an economy of at least 50 per 

 cent, on the side of petroleum, the boiler pressure being from 1 20 

 lbs. to 130 lbs. and the gross load over 400 tons. At the same 

 time the weight of fuel used, as against coal, is diminished by 

 about 50 per cent. , which is a most important item. 



" Although petroleum is scarcely a product of Western Europe, 

 we have to notice on the other hand the progress which has 

 lately been made in the extraction of oil as a waste product from 

 coal, &c. Mr. Jameson has extracted as much as nine gallons 

 per ton from mere shale. It is suggested that markets for such 

 oil will be difficult to find ; but it seems allowable to hazard the 

 idea that we may hereafter see our locomotives, even in England, 

 running with oil fuel, which would be at once much lighter and 

 much more easily renewed than the coal which is used at present, 

 and get rid of the intolerable nuisance of smoke and dirt. 

 There might in fact be an oil tank and a water tank side by side 

 at every stopping station, and the engine would replenish her 

 store of fuel at the same time as her store of water. 



"Another point in which speed and perfection of worlmanship 

 have gone hand in hand is the important industry connected with 

 textile fabrics. When Arkwright first brought his inventive mind 

 and mechanical skill to bear upon this subject, the tools he had 

 to work with were rude compared with the tools of the present 

 day, and could not produce the accurate work now attainable ; 

 and therefore the speed at which he was able to drive his spindles 

 was not remarkable. But our member, Mr. John Dodd, of 

 Messrs. Piatt Bros., informs me that the average speed of mule 

 spindles at Oldham, in new mills with new machinery, and 

 spinning No. 32 yarn from American cotton, is about 8500 revo- 

 lutions per minute ; whilst speeds as high as 9500 or even 10,000 

 revolutions have been attained. When we consider the delicate 

 nature of the material under treatment, the disastrous result of 

 the slighte-t hitch or unevenness in working, and the perfection 

 of mechanism required to bring up a multitude of spindles to such 

 a speed from that of the comparatively slow main shaft of the 

 mill, we may give every credit to the constructive skill which has 

 achieved such a result. In woollen mills (of which we hope to 

 see some excellent examples at Verviers on Thursday next) the 

 speed is 4000 revolutions per minute. The progress made here 

 has not been so great, mainly, in Mr. Dodd's opinion, from 

 wood being still adhered to as the material for the bobbin--. 

 Here therefore is a case where improved material may yet pro- 

 duce improved speeds ; but with cotton Mr. Dodd considers lhat 

 the extreme possibilities as to speed have been very nearly 

 attained. The limit however is imposed by the feebleness of the 

 material, not by any lack of skill or enterprise on the part of the 

 engineer. 'If higher speeds were required,' says Mr. Dodd, and 

 I fully believe him, ' we could make spindles which would be 

 equal to the demand.' 



" The construction of modern artillery, and with still greater 

 justice the methods of employing it, may properly be brought 

 under the scope of this address. I doubt whether of late years any 

 mechanical appliances or arrangements have given greater impetus 

 to skilful work and to the improvement of materials, especially 

 of steel. Twenty-five years ago the largest piece of ordnance in 

 use was a gun weighing 4J tons, firing with a maximum charge 



