492 



BREAD 



Tho baking temperature of the oven is from 420 to 450 F., -which is ascertained by 

 a thermometer with which the oven is provided. 



With respect to Holland's oven, Messieurs Boussingault, Payen, and Poncelet, in 

 their report to the Institute of Franco ; Gaultier do Glaubry, in a report made in the 

 name of the Committee of Chemical Arts to the Societi d'Encouragement ; and the late 

 M. Arago, represented that oven as successfully meeting all the conditions of salubrity, 

 cleanliness, and hygiene. Wood, coals, ashes are likewise banished from it, and 

 neither smoke nor the heated air of the furnace can find access to it. As in Perkins', 

 the furnace is placed at a distance from the mouth of the oven, but instead of con- : 

 veying the heat by pipes, as in the hot-water oven, it is the smoke and hot air of the 

 furnace which, circulating through fan-shaped flues, ramifying under the floor and 

 spreading over the roof of the oven, impart to it the requisite temperature. The floor 

 of the oven, on which the loaves are deposited, consists of glazed tiles, and it can 

 thus be kept perfectly clean. Tho distinctive character of M. Holland's or^u, how- 

 ever, is that the glazed tiles just spoken of rest upon a revolving platform which the 

 workman gradually, or from time to time, moves round by means of a small handle, 

 and without effort. 



Figures 230 to 239 represent the construction and appearance of M. Holland's oven 

 on a reduced scale. 



230. Front elevation. 



231. Vertical section through the 



axis of the fire-grate. 



232. Ditto, ditto. 



233. Elevation of one of the vertical 



flues. 



234. Suspension of the floors. 



235. Plan of the first floor. 



236. Plan of the sole. 



237. Plan of the second floor. 



238. Plan of the fire-grate and flues. 



239. Plan of the portion under 



ground. 



230 



When the oven has to be charged, the workman deposits the first loaves, by means 

 of a short peel, upon that part of the revolving platform which lies before the mouth 

 of the oven, and when that portion is filled, he gives a turn with the handle, and 

 proceeds to put the loaves in the fresh space thus presented before him, and so on 

 until tho whole is filled up. The door is then closed through an opening covered 

 with glass, and reserved in the wall of tho oven, which is lighted up with a jet of gas, 

 or by opening the door from time to time the progress of the baking may be watched ; 

 if it appears too rapid on ono point, or too slow on another, the journeyman can, by 

 means of the handle, bring the loaves successively to the hottest part of the oven, and 

 vice versd, as occasion may require. The oven is provided with a thermometer, and, 

 in an experiment witnessed, tho temperature indicated 210 C. = 420 F., the baking 

 of a full charge was completed in one hour and ten minutes, and the loaves of tho 

 same kind were so even in point of size and colour that they could not be distin- 

 guished from each other. 



The top of tho oven is provided with a pan for tho purpose of heating the water 

 necessary for the preparation of the dough, by means of the heat which in all other 

 plans (Mouchot's excepted) is lost. The workman should take care to keep always 

 some water in that pan, for otherwise the leaden pipe would melt and occasion 

 dangerous leaks. For this and other reasons, the safest plan, however, would be to 



