Sept. 28, 1888.] 



SCIENTIFIC NEWS. 



33i 



is also used for two 12 h.p. (nominal) Otto engines, which 

 pump water, and drive a dynamo for electric lighting. 

 The average cost of the gas is about 2d. per 1,000 c. ft., 

 including wages, repairs, and all incidental expenses, or 

 about 8d. for the equivalent of 1,000 c. ft. of ordinary 

 lighting gas. The anthracite costs about 13s. per ton. 



This gas is used on a large scale at the cocoa works 

 of Messrs. Van Houten & Son, of Messrs. Cadbury 

 Brothers, and of Messrs. Russ-Suchard & Co. Careful 

 trials at the first-named works showed that the cost 

 was under i|d. per 1000 c. ft., or only 6gd. for the 

 equivalent of 1000 c. ft. of the town lighting gas, 

 with which comparative tests were made. The anthra- 

 cite costs 1 6s. per ton. 



Messrs. Onderwater & Co., of Dordrecht, use the gas 

 for heating the drying chambers in their large starch 

 works. Messrs. Guittet, of Herblay,. have for some 

 years used it for making varnish, aria they not only 

 effect a considerable economy, but they avoid risk of 



gas of this kind can be and has been produced and 

 applied successfully, and there is every reason to believe 

 that its use will extend, especially as the gas-making 

 apparatus is easy to work. I am not at liberty to state 

 the annual saving effected by several firms who use the 

 gas, but it is very considerable. The cost of the gas 

 somewhat depends on that of the fuel and on the scale of 

 working, but, speaking generally, the equivalent of 

 1,000 c. ft. of ordinary lighting gas costs from 6d. to is. 

 Compared with solid fuel, gas has certainly many advan- 

 tages — it is under complete control, the heat derived 

 from it can be kept constant or varied at will, it is com- 

 paratively easy to insure complete combustion with but 

 little chimney draught, it is more economical, and 

 there is an entire absence of smoke. When solid fuel 

 is used, it is necessary to introduce more than twice the 

 quantity of air theoretically required for combustion, in 

 order to drive away, the products of combustion and to 

 insure a sufficiency of oxygen being brought into contact 



Fig. 3. — The Dowson Gas Plant on a Large Scale, as used at the Cocoa Works 

 of Messrs. Van Houten and Son, Holland. 



fire from the boiling over of the oil and gums, and this 

 of itself is an important consideration in varnish works. 



The gas is also used by the Societe Nestle for solder- 

 ing their condensed milk tins, and more recently it has 

 been adopted by Messrs. Huntley, Bourne, and Stevens, 

 of Reading, not only for soldering biscuit tins, but for 

 heating a large number of ovens in which japanned and 

 varnished goods are baked. 



Messrs. Hillman, Herbert, and Cooper use it at their 

 Coventry works, and in Germany, for brazing with blow- 

 pipes the joints of bycicles and tricycles as well as for 

 enamelling. 



On the Continent several firms use the gas for singe- 

 ing silk yarns and textile fabrics. It is also used by 

 several linen manufacturers in the North of Ireland for 

 stentering, which was formerly done with hot air. 



This gas is also used for melting type metal, for 

 heating hat forms, and for other work in a hat manufac- 

 tory. It has also been adopted for glass-blowing in an 

 electric-lamp factory, and for many other industrial pur- 

 poses. I have, however, mentioned enough to show that 



with the surfaces of the fuel. This large supply of air 

 can only be drawn in by a strong chimney draught or 

 other artificial means, and this causes a very rapid with- 

 drawal of heat from the fire. Further than this there is 

 invariably some escape of smoke and partially bur.it 

 carbon in the form of carbonic oxide. 



It is admitted that there is a demand for fuel gas, but 

 for many purposes the ordinary lighting gas is too ex 

 pensive, and the mere fact that it is made for light- 

 ing renders it so expensive. The percentage of illu- 

 minating constituents in coal gas is indeed very small 

 — 20 candle-power gas containing about 6| per cent., and 

 16 candle-power gas, as in London, containing only 

 about 4 per cent. The remaining 93J or 96 per cent, is 

 composed of non-luminous heating gases, but the addi- 

 tion of this small proportion of illuminants adds greatly 

 to the trouble and cost of producing the gas, and any 

 great reduction of its present cost is improbable. It is 

 therefore rational to suppose that for fuel purposes the 

 lighting constituents should be dispensed with. 



Assuming that we have a good and cheap fuel gas 



