?3Q 



SCIENTIFIC NEWS. 



[Sept. 7, iS 



may be used) in the fuel that is consumed, it is, nevertheless, a 

 satisfaction to know that great economical progress has been made, 

 and that the 6 or 7 lbs. of fuel per horse-power per hour con- 

 sumed by the very best engines of Watt's days, when woiking with 

 the aid of condensation, is now brought down to about one-fourth 

 of this consumption ; and this in portable engines, for agricultural 

 purposes, working without condensation — engines of small sire, 

 developing only 20 horse-power ; in such engines the consumption 

 has been reduced to as little as 1 "85 lb. per brake horse-power per 

 hour, equal to 165 lb. per indicated horse-power per hour, as was 

 shown by the trials at the Royal Agricultural Society's meeting at 

 Newcastle last year — trials in which I had the pleasure of par- 

 ticipating. 



In these trials, Mr. William Anderson, one of the Vice-Presidents 

 of Section G, and I were associated, and, in making our report of 

 the results, we adopted the balance-sheet system, which I suggested 

 and used so long ago as 1873 (see vol. 52, pages 154 and 155, of 

 the " Minutes of Proceedings of the Institution of Civil Engineers "), 

 and to which I alluded in my address as President of G at 

 Montreal. 



I have told you that the engineer of fhe present day appreciates 

 the value of the "next-to-nothings." There is an old housekeep- 

 ing proverb that if ym take care of the farthings and the 

 pence, the shillings and the pounds will take care of themselves. 

 Without the balance-sheet one knows that for the combustion of 

 I lb. of coal, the turning into steam of a given quantity of water at 

 a given pressure is obtained. It is seen, at once, that the result is 

 much below that which should be had, but to account for the 

 deficiency is the difficulty. The balance-sheet, dea ; ing with the 

 most mil, ute sources of loss — the farthings and the pence of econo- 

 mic working — brings you face to face with these, and you find that 

 improvement must be sought in paying attention to the " next-to- 

 nothings." 



Just one illustration. The balance-sheet will enable you at a 

 glance to answer this, among many important questions. Has the 

 fuel been properly burnt ?— with neither too much air, nor too little. 



At the Newcastle trials our knowledge as to whether we had 

 the right amount of air for perfect combustion was got by an 

 analysis of the waste gases, taken continuously throughout the whole 

 number of hours' run of each engine, affording, therefore, a fair 

 average. The analysis of any required portion of gases thus obtained 

 was made in a quarter of an hour's time by the aid of the admirable 

 apparatus invented by Mr. Stead, and. on the occasion to which I 

 refer, manipulated by him. In one instance an excess of air had 

 been supplied, causing a percentage of loss of 6'34- In the instance 

 of another engine there was a deficiency of air, resulting in the pro- 

 duction of caibonic oxide, involving a loss of 4 per cent. The 

 various percentages of loss, of which each one seems somewhat 

 unimportant, in the aggregate amounted to 28 per cent., and ihis 

 with one of the best boilers. This is an admirable instance of the 

 need of attention to apparently small things. 



I have already said that we now know the steam-engine is really 

 a heat-engine. At the York meeting of our Association I ventured 

 to predict that, unless some substantive improvement were made 

 in the steam-engine (of which improvement, as yet, we have no 

 notion), I believed its days, for small powers, were numbered, and 

 that those who attended the centenary of the British Association in 

 19 3 1 would see the present steam-engines in museums, treated as 

 things to be respected, and of antiquarian interest to the engineers 

 of those days, such as are the open-topped steam cylinders of New- 

 comen and of Smeaton to ourselves. I must say I see no reason, 

 after the seven years which have elapsed since the York meeting, 

 to regret having made that prophecy or to desire to withdraw it. 



The working of heat-engines, without the intervention of the 

 vapour of water, by the combustion of the gases arising from coal, or 

 from coal and from water, is now not merely an established fact, 

 but a recognised and undoubted, commercially economical, means of 

 obtaining motive power. Such engines, developing from I to 40 

 horse power, and worked by the ordinary gas supplied by the gas 

 mains, are in most extensive use in ptinting works, hotels, clubs, 

 theatres, and even in large private houses, for the working ofdynamos 

 to supply electric light. Such engines are also in use in factories, 

 being sometimes driven by the gas obtained from "culm" and 

 steam, and are giving forth a horse power for, it is stated, as small a 

 consumption as one pound of fuel per hour. 



It is hardly necessary to remind you — but let me do it— that, 

 although the saving of half a pound of fuel per horse power 

 appears to be insignificant, when stated in that bald way, one 

 realises that it is of the highest importance when that half-pound 

 turns out to be 33 per cent, of the whole previous consumption of 

 on £., of lhose economical engines to which I have referred. 



The gas-engine is no new thing. As long ago as 1807, a M. 

 de Kivaz proposed its use for driving a carriage on ordinary roads, 



For anything I know he may not have been the first proposer. It 

 need hardly be said that in those days he had not illuminating 

 gas to resort to, and he proposed to employ hydrogen. A few 

 years later, a writer in Nichc'lson's Journal, in an article on 

 " flying machines," having given the correct statement that all that 

 is needed to make a successful machine of this description is to 

 find a sufficiently light motor, suggests that the direction in which 

 this may be sought is the employment of illuminating gas, to 

 operate by its explosion on the piston of an engine. The idea of 

 the gas-engine was revived, and formed the subject of a patent by 

 Barnett in the year 1838. It is true this gentleman did not know 

 very much about the subject, and that he suggested many things 

 which, if carried out, would have resulted in the production of an 

 engine which could not have worked ; but he had an alternative 

 proposition which would have woiked. 



Again, in the year 1 861, the matter was revived by Lenoir, and 

 in the year 1865, by Hugon, both French inventors. Their engines 

 obtained some considerable amount of success and notoriety, and 

 many of them were made and used ; but in the majority of cases 

 they were discarded as wasteful and uncertain. Tne Institution of 

 Civil Engineers, for example, erected a Lenoir in the year l86S, to 

 work the ventilating fan, but after a short time they were compelled 

 to abandon it, and to substitute a hydraulic engine. 



At the present time, as I have said, gas-engines are a great com- 

 mercial success, and they have become so by the attention given to 

 small things, in popular estimation — to important things, in fact, 

 with which, however, I must not trouble you. Messrs. Crossley 

 Brothers, who have done so much to make the gas-engine the com- 

 mercial success that it is, inform me that they are prosecuting 

 improvements in the direction of attention to detail, from which, 

 they are obtaining greatly improved results. 



But, looking at the wonderful petroleum industry, and at the 

 multifarious products which are obtained from the crude material, 

 is it too much to say, that there is a future for motor engines, 

 worked by the vapour of some of the more highly volatile of these 

 products — true vapour — not a gas, but a condensable body, capable 

 of being worked over and over again? Numbers of such engines, 

 some of as much as 4 horse power, made by Mr. Yarrow, are now 

 running, and are apparently giving good results ; certainly excellent 

 results as regards the compactness and lightness of the machinery ; 

 for boat purposes they possess the great advantage of being rapidly 

 under way. I have seen one go to work within two minutes of the 

 striking of the match to light the burner. 



Again, as we know, the vapour of this material has been used as 

 a gas in gas-engines, the motive power having been obtained by 

 direct combustion. 



Having regard to these considerations, was I wrong in predicting 

 that the heat-engine of the future will probably be one independent 

 of the vapour of water? And, further, in these days of electrical 

 advancement, is it too much to hope for the direct production of 

 electricity from the combustion of fuel ? 



As the world has become familiar with prime movers, the desire 

 for their employment has increased. Many a householder could 

 find useful occupation for a prime mover of 5 or \ horse power, 

 working one or two hours a day ; but the economical establishment 

 of a steam-engine is not possible until houses of very large dimen- 

 sions are reached, where space exists for the engine, and where, 

 having regard to the amount of work to be done, the incidental 

 expenses can be borne. Where this cannot be, either the prime 

 mover, with the advantages of its use, must be given up as a thing 

 to be wished for, but not to be procured, or recourse must be had 

 to some other contrivance — say' to the laying on of power, in some 

 form or another, from a central source. 



I have already incidentally touched upon one mode of doing this, 

 namely, the employment of illuminating gas, as the woiking agent 

 in the gas-engine ; but there are various other modes, possessing 

 their respective merits and demerits— all ingenious, all involving 

 science in their application, and all more or less in practical use — 

 such as the laying-on of special high-pressure water, as is now being 

 extensively practised in London,-in Hull, and elsewhere. Water at 700 

 lbs. pressure per inch is a most convenient mode of laying on a large 

 amount of power, through comparatively small pipes. Like electricity, 

 where, when a high electro-motive force is used, a large amount of 

 energy may be sent through a small conductor, so with water, under 

 high pressure, the mains may be kept of reasonable diameters, with- 

 out rendering them too small to transmit the power required through 

 them. 



Power is also transmitted by means of compressed air, an agent 

 which, on the score of its ability to ventilate, and of its cleanliness, 

 has much to recommend it. On the other hand, it is an agent 

 which, having regard to the probability of the deposition of mois- 

 ture in the form of " snow," requires to be worked with judgment. 

 Again, there is an alternative mode for the conveyance of power 



