390 TRANSACTIONS OF SECTION B. 



smoke nuisance in all tlie large centres of population. The grate, which is 

 designed to yield as much radiant heat as possible from the fuel, supports an 

 upright wall of coke, 4 to 4^ inches from back to front, and varying in width 

 from 8 to 24 inches, according to the size of the room to be heated. The grate 

 consists of a series of slender horizontal bars in front and a firebrick slab 

 underneath and at the back. There are ten such bars, each successive pair 

 being two inches apart, so that the height of the grate from the base to the top 

 is 25 inches. It is filled to the top with coke, and on this is laid paper and 

 wood, or other fire-lighter, and a layer of coke with a few pieces of coal reaching 

 nearly to the throat of the chimney. The fire burns from the top downwards. 

 The grate is charged each morning with an amount of fuel sufficient to 

 last the whole of the day, and, the fuel having been lighted at the top, no 

 replenishment is needed during the day.' In the speaker's opinion the essential 

 features of a good grate are : — 



(1) The face of the fire should be vertical, so that the chief radiation shall be 

 horizontal and not directed towards the chimney and the ceiling. 



(2) The bars should be as slender as is compatible with sufficient strength, 

 and be fixed as wide apart as will suffice to prevent more than an 

 occasional ember falling out ; 



(3) The fire should be narrow from back to front, for glowing embers which 

 cannot be seen through the front do not radiate heat into the room ; 



(4) Air should pass in through bars in front, not through bars beneath ; for 

 the most vivid combustion occurs where the air and fuel meet ; 



(5) All the fuel needed during the day should be put in at once at the 

 beginning, and it should be lighted at the top and burnt downwards ; 



(6) It is well to have two iron plates to divide the fuel into sections for 



checking the fire, and either plates or doors, closing in front of the 

 upper bars, to draw the fire up when necessary. 



(v.) Recent Improvements in Gas-Fires. 



Mr. H. James Yates (Birmingham), who had contributed a paper on ' Recent 

 Improveniients in Gas-Fire Science ' to the discussion upon ' Fuel Economy ' 

 (Section B) at the Birmingham Meeting of the Association in 1913,* gave the 

 following account of his more recent investigations in the direction of further 

 improvements in the ventilating effect of gas-fires, which had culminated in a 

 notable advance in this important respect : — 



Originally the gas-fire was as nearly as possible an imitation of the coal- 

 fire. It consisted of Bunsen burners so arranged that their flames should play 

 on some incombustible material, so as to bring it to a red heat or something 

 approaching this state. It lost much heat up the chimney, and it gave very 

 little radiant heat; the cost of the gas used was out of all proportion to the 

 amount of heat obtained ; also, the fire was apt to smell, owing to the incomplete 

 combustion of the gas. Gradually it was recognised that if the gas-fire was to 

 be made practically efficient on a commercial scale, its economic and hygienic 

 aspects must be. studied. At first the economic aspect was almost exclusively 

 dealt with, effort being made to extract more heat from the waste products 

 before their escape by the chimney, and the heat thus extracted being returned 

 to the apartment as heated air. In other words, these early efforts in gas- 

 fire economy aimed at concentrating on convected heat. There was undoubted 

 economy effected, but unfortunately it was accompanied by a bad physiological 

 effect. The convection currents were so hot that the percentage saturation of 

 the air of the apartment was lowered, with the result that moisture was 

 abstracted from the skin and mucous membranes of the occupants, and they 

 suffered unpleasant sensations of dryness, prickling of the skin, and so on. 

 Further, owing to the air of the room being hotter than the walls (because_ of 

 the heat being mainly transferred to the latter by the medium of the air), 

 persons sitting near these, while feeling discomfort owing to the overheated air, 



' For details and photographs see Journal of the Eoyal Society of Arts, 

 vol. Ixiii., 1915, pp. 570581. 



■' B.A. L''i>urts, 1913, Birmingham, p. 435 (7). 



