Jtdy II, 1878] 



NATURE 



275 



consumption of a certain quantity of heat in the steam- 

 engine, the blast-furnace, and other methods of utilising 

 this source of power as derived from coal, and points out 

 how, by means of electricity, this agent may be made to 

 do a greater amount of work for us than ever. The won- 

 derful results obtained from the Siemens' dynamo-electric 

 machine are well known, and Dr. Siemens gives an 

 example of the saving of power that might be effected by 

 its use : — 



" Let us suppose that at some central station 100 horse- 

 power of steam or water power was employed to give 

 motion to several dynamo-electric machines of the dimen- 

 sions found most convenient in practice, and that by 

 means of metallic conductors of suitable dimensions the 

 electric current produced at the central station was con- 

 ducted to a number of halls or factories requiring to be 

 lighted, or to utilise mechanical power. If illumination 

 were the only object in view, the total amount of light 

 that could be thus produced would be equal to 125,000 

 candle-power. This would be equivalent to 6,250 Argand 

 burners, each of 20 candle-power, at a consumption per 

 burner of 6 cubic feet of gas per hour, or a total consump- 

 tion of 37,500 cubic feet of gas to produce the same effect 

 of light. This would require 3| tons of coal, and the 

 electric light about as many hundredweights." 



Now if the power to drive these machines could be ob- 

 tained apart from coal the addition to our mechanical 

 resources would be immense. While Dr. Siemens shows 

 that the tides are a source of power that might be utilised 

 directly or indirectly, he at the same time shows that the 

 results would not be at all commensurate to the work 

 expended. But the old sources of power, which have 

 gradually given way before the universal introduction of 

 steam — wind and falling water — might again be called 

 into play, and with infinitely greater effect than ever. It 

 is evident that within certain limits the rotatory motion 

 required for the working of the dynamo-electric machine 

 might be effected by means of the old-fashioned windmill, 

 and to a much greater extent by means of falling water. 

 Our readers may remember that Dr. Siemens, some 

 months ago, in an address which he then gave, referred 

 to the immense quantity of power which flowed ready 

 made over the Falls of Niagara. In his Glasgow address 

 he again referred to the subject, in order to show how 

 this gigantic source of power might be utilised to pro- 

 duce action at a distance. "When," he says, "little 

 more than a twelvemonth ago I visited the great Falls of 

 Niagara, I was particularly struck with the extraordinary 

 amount of force which is lost, as far as the useful pur- 

 poses of man are concerned. 100,000,000 of tons of 

 water fall there every hour from a vertical height of 1 50 

 feet, which represent an aggregate of 16,800,000 horse- 

 power, producing as their effect no other result than 

 to raise the temperature of the water at the foot of 

 the fall 



150 

 772 



= zo Fahr. 



In order to reproduce the power of 16,800,000 horses, or, 

 in other words, to pump back the water from below to above 

 the fall, would require an annual expenditure of not less 

 than 266,000,000 of tons of coal, calculated at an average 

 consumption of 4 lbs. of coal per horse-power per hour : 



which amount is equivalent to the total coal consump- 

 tion of the world. In stating these facts in my inaugural 

 address on assuming the presidency of the Iron and Steel 

 Institute, I ventured to express the opinion that in order 

 to utilise natural forces of this description at distant 

 towns and centres of industry the electric conductor 

 might be resorted to. This view was at that time un- 

 supported by experimental data such as I have been able 

 since then to collect." Dr. Siemens then shows what has 

 been done in conveying the electric light to a distance ; 

 and he points out that, " if mechanical force is required 

 to be distributed, the arrangements are in every respect 

 similar to those for the distribution of electric light ; and 

 it has been proved experimentally that the amount of 

 power recovered at the distant station is nearly equal to 

 half the power employed at the central station." Even 

 as regards the consumption of coal, were that article 

 used. Dr. Siemens shows that the magneto-electric 

 machine is cheaper than the gas or steam-engine. But 

 he rightly says : — " It would not be necessary to seek on 

 the other side of the Atlantic for an application of this 

 mode of transmitting the natural force of falling water, 

 as there is perhaps no country where this force abounds 

 to a greater extent than on the west coast of Scotland, 

 with its elevated lands and heavy rainfalls. You have 

 already conducted the water of one of your high-level 

 lochs to Glasgow by means of a gigantic tube ; and how 

 much easier would it be to pass the water in its descent 

 from elevated lands through turbines, and to transmit 

 the vast amount of force that might thus be collected, 

 by means of stout metallic conductors, to towns and 

 villages for the supply of light and mechanical power ! " 



Dr. Siemens points out other directions in which the 

 natural forces of the universe might be used for the pur- 

 poses of man, without resorting, to such an extent as we 

 do at present, to our coal supplies. While windmills are 

 directly rather an uncertain source of power, still, he shows 

 that a number of windmills, such as may be constantly 

 seen working in Holland for the drainage of the land, 

 might, for instance, be employed to raise water, by 

 pumping, to an elevated lake or reservoir, whence the 

 power could be drawn off by means of hydraulic motors 

 when required, and might be conducted electrically to 

 centres of habitation. 



We ought to be grateful to Dr. Siemens for taking so 

 much pains to lighten up the gloomy prospects which 

 some pessimists have been presenting to us for some 

 years past ; and to those who may be cynical enough to 

 reply that a return to the windmill and the water-wheel 

 is simply a sign of the prophesied retrogression, we may 

 fitly reply, in Dr. Siemens' own words : — 



" It would be wrong to suppose that a resumption ot 

 the use of natural forces would throw us back to the 

 time of the windmill and the primitive water-wheel which 

 used to give motion to isolated establishments. We 

 shall have learned to store, to transport, and to utilise 

 these forces in a manner adapted to our superior re- 

 quirements ; and who knows whether the time may not 

 come when our descendants in the third or fourth 

 generation will look back upon the indiscrimate users of 

 coal with something like the same feeling that we look 

 upon the users of flint and bronze implements. Indeed, 

 without waiting for the extinction of our coal-fields, it 



