474 



NA TURE 



{Sept. 



problem of employing a single wire to be at one and the same 

 time the transmitter of multiple electric messages, and messages 

 in opposite directions. Then, thanks to the application of Fara- 

 day's great discovery of induced electricity, there has been, 

 during the last quarter of a century, the progressive development 

 of the dynamo machine, whereby the energy of ordinary motors, 

 such as steam-engines, is converted into electrical energy, com- 

 petent to deposit metals, to (as has already been said) fuse them, 

 to light not only isolated buildings but extensive areas of towns 

 and cities, and to transmit power to a distance, whether for 

 manufacturing purposes or for the railway or tramcar ; and thus 

 the miracle is performed of converting a waterfall into a source 

 of light, as at Sir William Armstrong's house, or into the origin 

 of power for a railway, as at the Giant's Causeway. To the 

 application of electrical science is due the self-exciting of the 

 dynamos and the construction of secondary batteries, enabling 

 a development of electricity to be continued for many hours. In 

 the United Kingdom general electric lighting, that is to say, the 

 lighting of large sections of a town from a central station, has 

 been stopped by the most unwise, because most unjust, condi- 

 tions imposed by the Government General Electric Lighting Acl 

 of 1882. A new and meritorious industry, which should have 

 been granted the same privileges as are accorded to other in- 

 dustrial undertakings needing Parliamentary powers, « 

 jected to this most unjust condition : that at the end of twenty- 

 1 me years the public authority of the town or place ligh 

 have the option of buying the undertaking for the then value of 

 the mere materials, and that, if the authority did not choosi to 

 purchase (for it was not bound to buy), at every subsequent five- 

 year period this option should re-arise ; that is to say, that a 

 new undertaking, which would require years for its general ac- 

 ceptance (for the public is slow to take up a novelty), was, after 

 the experimental and non-paying stage had been passed, to be 

 practically forthwith taken away for a mere fraction of the capital 

 that had been outlaid if the undertaking paid, but was not to be 

 taken away if it did not pay. Such, in spite of the teaching of 

 Section F, is the condition to which our Government has arrived 

 in respect of economic science. The next electrical matter I 

 have to touch upon, that of the telephone and microphone, with 

 wdiich will for ever be associated the names of Graham-Bell, 

 Edison, and Hughes, has, as regards the public use 'if the tele- 

 phone, been all hut similarly treated in the United Kingdom. 

 It has been declared to be within the telegraphic monopoly given 

 by Parliament to the Post Office nine years before the telephone 

 was invented, and the power to use it depends entirely upon the 

 grace and favour of the Post Office, a grace and favour not 

 always aco rded : and even 1 ', iupled with limita- 



tions as to distance, and coupled with a condition of payment of 

 10 per cent, of the gross receipts by the companies to the Post 

 Office as a royalty ; and all this because Government has be- 

 come a trader in electrical intelligence, and fears the competition 

 of the telephone with its telegraphs. 



No one in the ship-loving countries of England, C ■ 

 the United States can refrain from feeling the warmest interest 

 in all connected with navigation, and we know how frequently, 

 alas ! the prosperous voyage across the wide and 

 ocean ends in shipwreck and disaster when the wished-for shore 

 is approached, and when the sea is comparatively shallow. Ex- 

 cept for the chance of collision, there is in a staunch ship little 

 danger in the open ocean, but on nearing the shore, not only is 

 the liability to collision increased, but shoal, and sun 

 render navigation perilous, and it is on the excellence of the 

 lighthouses and lightships that (coupled with soundings) the 

 sailor relies. These structures and appliances are confided to 

 the engineer, and to be efficient they require him to be able to 

 apply the teachings of Section A in optical science, and in the 

 case ol fogs, or as regard- buoys at night-time, the science of 

 sound. I parenthetically alluded to soundings as one (indeed a 

 principal one) of the safeguards of ships when approaching 

 shore. It is important in these days of high speed that these 

 should be made with ease and without the necessity of stopping 

 the ship, or even of diminishing its velocity. Sir William 

 Thomson, by the application of the science of pneumatics, has 

 enabled this to be done. Again, most important is it that the 

 compass, amidst all the difficulties attendant upon its being 

 situated on an iron or steel structure, should be trustworthy. 

 And here Sir William has applied the science of magnetism in 

 his improved compass to the practical purposes of navigation. 



To go to another important branch of engineering — water- 

 supply. The engineer dealing with a district to be fed from the 

 surface will find himself very deficient if he have not the power 



of applying the science of meteorology to the work that he has 

 in hand ; he must know, not the average rainfall, for that is of 

 but little use to him, but the maximum, and, most important of 

 all, the minimum, rainfall over a consecutive period of years : the 

 maximum, so that he may provide sufficient channels and by- 

 washes for floods ; the minimum, so as to provide sufficient 

 storage. He must know what are the losses by evaporation, 

 what are the chances of frost interfering with his niters and with 

 his distributive plant. 



Coming to the mathematical side of Section A — whether we 

 consider the naval architect preparing his design of a vessel to 

 cleave the waves with the least resistance at the highest speed, 

 or whether we consider the unparalleled series of experiments of 

 that most able Associate of Naval Architects, the late William 

 Froude, carried out as they were by means of models which 

 were admirable in their material, their mode of manufacture 

 with absolute accuracy to the desired shape, and their mode of 

 traction and of record, we must see that both architect and ex- 

 perimenter should be able to apply mathematical science to their 

 work, and that it is in the highest degree desirable that they 

 sh uld possess, as Froude did, those most excellent gifts, science 

 and practical knowledge. 



Again, the mathematical side of Section A has to be applied 

 by engineers when considering the strength and proportion of 

 boilers, ships, bridges, girders, viaducts, retaining walls, and in 

 short the whole of the work with which an engineer is intrusted. 

 Notable instances of great bridges will occur to all our minds, 

 especially meeting as we are in this continent of grand streams, 

 Eads' St. Louis Bridge, Roebling's Niagara Bridge, and his and 

 and his sons' East River Bridge, Gzowski's International Bridge, 

 and, going back to our own land, Fowler and Baker's Bridge 

 over the Forth. 



I from Section A to Section B, there is evidently so 



much overlapping of these Sections that a good deal that I have 

 said in reference to Section A might properly have been reserved 

 for Section B. The preparation from the ore of the various 

 metals is in truth a branch of engineering ; but to enable this to 

 be accomplished with certainty, with economy, involving the 

 not throwing away of that wdiich is called the waste product 

 but which is frequently a valuable material, it is essential that 

 tin- engineer and the chemist should either be combined in one 

 and the same person, or should go hand in hand. In the manu- 

 facture of pig iron it is absolutely necessary that the chemical 

 constituents of the ore, the fuel, and the flux should be thoroughly 

 understood, and that the excellence of the process followed 

 should be tested by an analysis of the slag. For want of this 

 chemical knowledge, thousands upon thousands of tons of bad 

 pig iron have been made, and thousands upon thousands of tons 

 were formerly left in the issuing slag. Similar remarks apply to 

 the production of lead and of copper from the ores, and still 

 more do they apply to that great metallurgical manufacture of 

 the last few years — " steel." In the outset steel was distrusted, 

 because of the uncertainty of its behaviour, but the application 

 of chemical science now enables the manufacturer to produce 

 with precision the material required to fulfil the physical tests 

 imposed by the engineer. 



Reverting to the water engineer, the chemist and the micro- 

 scopist have their sciences applied to ascertain the purity of the 

 intended source, and, as in the case of Clarke's beautiful pro- 

 cess, by the application of chemistry, water owing its hardness 

 to that common cause, carbonate of lime, is rendered as soft as 

 the water from the mountain lake. Taking that other branch 

 of engineering commonly coupled with water, viz. the supply of 

 gas, the engineer is helpless without the application of chemistry. 

 From the examination of the coal to be used to the testing of 

 the gas to lie supplied, there is not one stage w here chemical 

 science is not necessary. The consumer requires gas which shall 

 lie as nearly as possible a pure hydrocarbon of high, illuminating 

 power, and it might well have been that a person to whom was 

 delivered the crude gas as it issued from the retort would have 

 said, "Certain things may be separated out more or less, but to 

 practise on a wholesale scale the delicate operations which wdll 

 be needed to cleanse the illuminating gas from its multifarious 

 accompanying impurities is a hopeless undertaking, and must 

 be so, if for no other reason than this — the excessive cost that 

 would be entailed." But what are the facts ? Although I for 

 one do not like to sit in a room where gas is burnt, unless 

 special provision is made for taking away the products of com- 

 bustion, the engineer of the present day, thanks to the applica- 

 tion of chemical science, delivers gas to the consumer in a state ol 

 c parative purity (although it may have been made from impure 



