1886.] on Dissociation Temperatures, &c. 481 



the room. Owing to the high temperature of the regenerative gas 

 flame and the employment of a reflector, which would be quite impos- 

 sible with an ordinary fire, the economy of fuel attained by the use 

 of this stove, and in a less degree by the use of the chimney fire, is 

 considerable. The maximum consumption of gas in the stove exhi- 

 bited is about 12 cubic feet per hour. Considering that the gas 

 need not burn constantly, or may be lowered as required, its daily 

 consumption may be set down at 50 to 150 cubic feet of gas for an 

 ordinary room of about 4000 to 5000 cubic feet capacity. 



There is still one very important point which remains to be 

 mentioned in connection with a regenerative gas flame of high 

 intensity, provided with a reflecting background ; that is, the better 

 distribution of the radiated heat. I find that a room warmed by 

 means of a stove or open fire, such as described, is of a more uniform 

 temperature than when warmed by an ordinary fire or by a gas and 

 coke fire," such as my brother was engaged in introducing into this 

 country shortly before his death. 



This, in my opinion, is mainly due to the fact that a source of 

 radiant heat of low intensity but of large surface, sending out its 

 rays at various angles, heats an object in its vicinity very much more 

 than is the case with a smaller source of radiant heat of greater 

 intensity, whose rays strike the object from one direction only, not- 

 withstanding that both sources radiate the same quantity of heat. 

 This action is illustrated by means of the two diagrams exhibited, 

 Figs. 11 and 12, which represent two rooms, the one, Fig. 12, 

 heated by a small flame of high intensity, and the other. Fig. 11, 

 by a large flame of low intensity, both radiating the same 

 quantity of heat. In each room two objects, globes or spheres, 

 are represented, the one close to, and the other at a distance from 

 the source of heat. The object in the one room near to the source 

 having the large heating surface is almost enveloped in rays, while 

 that in the second receives rays only in one direction, the former there- 

 fore being much more heated than the latter. This difference does not 

 occur when the two globes at a distance from the two sources of heat 

 are compared. The law that the rays of heat are diminished in the 

 inverse ratio of the square of the distance is only correct as regards 

 small but intense sources of heat, whilst the decrease of radiant heat 

 takes place in a much higher proportion, in the case of large sources 

 of heat of low intensity. This clearly proves that for the purpose of 

 warming rooms by means of radiation, it is important that the heat 

 should be concentrated in an intensely hot focus, as is the case in 

 nature, our earth being warmed in this way by the radiant action of 

 the sun. 



From various considerations I am led to believe that the question 

 of sanitary and economical warming is one which commands a great 

 deal of attention in this country. Not many years ago I had to report 

 to my own Government on the Smoke Abatement Exhibition, held in 

 this city, and I understand that a Smoke Abatement Institution has 



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