TKANSACTIONS OF SECTION G. 823 



in small engines of from foiu- to twenty-five horse-power varies from 36 lbs. to 

 8^ lbs. per horse-power per hour, and, as it is estimated that compressed-air power 

 would reach the consumer at an expenditure of from 4-7 lbs. to 1-77 lbs. fuel per 

 horse-power per hour, a savinof of from 750 to 480 per cent, is effected. 



The works will be situated on land fronting Garrison Lane. The first portion 

 is laid out for the erection of fifteen engines of 1,000 horse-power each, to be worked 

 by Lane's patent boiler and Wilson's gas-producers. As the Company have 

 already received applications for over .3,600 horse-power, they have entered into 

 contracts for the completion of 6,000 horse-power at the Central Station before 

 May 31, 1887. The mains will all be of wrought iron, laid in concrete troughs 

 near the surface of the road, so that they can be easily got at for examination and 

 repairs. They will vary in size from twenty-four down to seven inches. Valves 

 will be provided, by which, in case of damage to any portion of main, that 

 portion will be automatically stopped off from the rest of the district, so as not to 

 interrupt the general service. The compressed air will be sold to users at a price 

 per 1,000 cubic feet of air of a standard pressure of 4.5 lbs., measured by a meter so 

 constructed as to register the volume delivered at the value of the standard pres- 

 sure, independently of any variations there may be in the main pressure. The 

 meter consumption of the various users will be registered in the gross on a dial at 

 the central works by electric apparatus, so that any waste or misuse of the air can 

 be at once discovered and prevented. 



The paper concludes with a discussion of the various economical aspects of the 

 question, pointing out that compressed air can be used for all purposes for which 

 steam is employed, except heating; air, on the other hand, has the advantage 

 over steam that it is available for refrigeration. 



4. Tlie Welsbach System of Gas-lighting hy Incandescence. 

 By Conrad W. Cooke. 



"This system, which is the invention of Dr. Carl Auer von Welsbach, of Vienna, 

 consists in impregnating fabrics of cotton or other substances, made into the form 

 of a more or less cylindrical hood or mantle, with a compound liquid composed of 

 solutions of Zirconia and Oxide of Lanthanum (or with solutions of Zirconia with 

 Oxides of Lanthanum and Yttrium), which mantle, under the influence of a gas 

 and air flame, is converted into a highly refractory material capable of withstanding 

 for long periods without change the highest temperatures that can be obtained 

 from the most eflicient form of atmospheric burners, and which, under the influence 

 of such temperatures, glows with a brilliant incandescence, very white and perfectly 

 steady, retaining, moreover, its woven or reticulated character ; the organic volatile 

 and carbonaceous matters being entirely burnt out and replaced by an incom- 

 bustible and highly refractory residual skeleton, which becomes by its brilliant 

 incandescence the source of light in the burner. 



The light emitted is, at a distance, hardly distinguishable from a twenty-candle 

 incandescence electric lamp, and by a modification of the composition of the im- 

 pregnating liquid a yellower light is obtained, resembling that of the best gas lights, 

 but much more brilliant, and wich a saving of gas of from fifty to seventy-five per 

 cent., and, being perfectly smokeless, it is incapable of giving ofi' solid carbon, 

 whereby ceilings or internal decorations are blackened. 



The illuminating power of the lights may be taken at about ten candles per 

 cubic foot of gas consumed per hour, and the mantles last from 800 to 1,500 hours. 



5. Boiler Explosions. By E. B. Marten. 



After mention of the work of the British Association as to this subject at the 

 Norwich, Exeter, Liverpool, Edinburgh, and Brighton meetings from 1868-1872, 

 and also the Parliamentary Committee of 1860-1871, a paper by the writer at 

 Liverpool in 1870 was quoted, recommending inquiries, independent of coroners' 



