344 



SCIENCE. 



[Vol. VII., No. 167 



burned in air with ordinary burners. Gas- 

 engines, moreover, are within the intelligence of 

 butlers, gardeners, and coachmen : they are 

 always ready for work, they attain their max- 

 imum efficiency at once, and they can be stopped 

 in a moment. 



In England the opportunities of using water- 

 power are few and far between. The power of 

 the tide or that of a flow of the river is very 

 small when utilized within the limits of ordinary 

 people. The whole flow of the Thames through 

 London bridge would maintain only 800 lamps. 

 In Scotland, however, the case is somewhat dif- 

 ferent. There several persons have utilized the 

 water stored up in lakes. Many wonder why the 

 wind is never used ; but, apart from its uncer- 

 tainty and unreliability, there is the fact that the 

 power developed by the best windmills is, on the 

 average, but very small. 



After referring to the sources of power, Mr. 

 Preece turned his attention to the dynamo, and 

 claimed that science, since the expiration of the 

 Gramme patent, has converted a crude instrument 

 into the most powerful converter of energy that 

 exists. The forms of dynamo, he said, are being 

 whittled down to two or three recognized shapes ; 

 but " as long as the spirit of rivalry is stirred up 

 by competition and emulation, so long shall we 

 have some manufacturer who will make a change 

 for the sake of a change, and who will advertise 

 his wares as the best in the world." Mr. Preece 

 holds that little remains to be desired in the 

 quality or price of dynamos, and that a well-con- 

 structed dynamo, kept clean and well lubricated, 

 never overworked, should last a lifetime without 

 much attention except to the brushes and com- 

 mutator. 



It is by means of the secondary battery that 

 regularity and uniformity of current are main- 

 tained in isolated installations ; and it supplies a 

 reserve of force that renders one free from acci- 

 dent to engine or dynamo. Its early failures dis- 

 appointed many ; but Mr. Preece hopes that it 

 has ' sown its wild oats,' and that it has become a 

 mature, sober, practical instrument. Sir William 

 Thomson writes, " My cells have worked to perfec- 

 tion. It is the greatest possible comfort to us in 

 the house to have the light with satisfactorily 

 equal brilliancy at all hours of the night and day, 

 and every day in the week. I have now cut off 

 the gas at the meter, so that there is absolutely 

 none used in the house. I have no oil-lamps, 

 and have not used so much as a single quarter of 

 a candle within the last three months, and have 

 the electric light in every part of the house where 

 light can possibly he wanted by night or by day." 

 Mr. Preece now uses the secondary batteries, not, 



as formerly, as regulators to his engine, but for 

 the storage of electricity, charging them during 

 the day, and discharging them through the lamps 

 at night. He maintains that the durability of his 

 cells is most satisfactory, and that he can see 

 no reason why they should not last ten years at 

 least. 



Of the lamps, Mr. Preece could not chronicle so 

 great progress as that of dynamos and secondary 

 batteries, and he held that a good standard glow- 

 lamp has not yet been devised. He would prefer 

 a 10-candle lamp, working under a pressure of 

 50 volts, and requiring half an ampere : that 

 would mean the absorption of 25 watts, or two 

 and a half watts per candle. The life of such a 

 lamp would not be very great ; but, if it were 

 cheap enough, one would not mind frequent re- 

 newals. Makers of lamps seem to consider that 

 there is great credit in securing long life ; but 

 this may be unfortunate, considering the de- 

 terioration of glow-lamps with age, owing to the 

 wasting-away of the carbon and its deposition on 

 the glass globe. Mr. Preece would have a lamp 

 such that we could afford to give it a ' short and 

 merry life.' 



There is felt in England, on account of the 

 small development in the industry, a difficulty in 

 obtaining experienced workmen ; and in some 

 cases it has been necessary to send nearly the 

 length of the island for men to put in the wires 

 and machinery. 



Mr. Preece's estimation of the cost is just twice 

 that of gas ; but this, whether too high or too 

 low, seems to be in doubt, and it is certain that 

 the cost is largely dependent upon the extent to 

 which the light shall be used. Considerable im- 

 patience is felt at the restrictions imposed by the 

 act of 1882, and the council of the Society of arts 

 is taking an active part in supporting the measure 

 now before the house of lords, intending to ex- 

 tend the facilities for introducing electric lighting. 

 This act is understood to be under the direct 

 supervision of Lord Rayleigh. 



THE PROPOSED FISHERIES BOARD OF 

 GREAT BRITAIN. 1 

 I am of opinion that the less the government 

 interferes with any branch of industry, the better, 

 and that, as a general rule, the cost and trouble 

 of obtaining such scientific information as is 

 necessary for the successful prosecution of a 

 branch of industry ought to fall upon those who 

 profit by it, and not upon the general body of the 



1 Letter in response to a request from the secretary of 

 the Society of arts for Professor Huxley's views as to the 

 constitution of a fisheries board. 



