UNFERMENTED BREAD. Under this heading we may briefly notice one or two improvements which have been introduced into the manufacture of AERATED BREAD, give some details supplementary to the article under the latter heading in vol. i. of the Encyclopcedk, and indicate the general bearings of this kind of baking, and of the bread thus produced, upon public health and upon the subject of medical dietetics. In 1863 the " Aerated Bread company (limited)" was established for purchasing from the patentee, Dr. Dauglish, the sole right of manufacturing this kind of bread in and around London; and from that time, the use of this new article of food has become much more extensive. Indeed, at the present day, Dauglish's aerated bread is manufactured (by purchase of the right to use the process) not only in most of the large towns in England, but also in Melbourne, Adelaide, and Sydney. In the working of the original patent, it was found that the pressure at the commencement of the process of driving the mixed ingredients from the iron box through a cock or tap at the bottom was so violent as to give almost an explosive expansion to the ejected portion of dough, causing the struc ture of the bread more to resemble whipped cream of froth than fermented bread. This was a point of greater importance than 'night have been anticipated, because it is found by experience that the flavor and other palatable qualities depend in a great measure on the internal arrangement of the loaf. Moreover a great part of the pressure obtained was entirely wasted A new patent was, after a time, taken out by Dr. Danglish, to improve the "piled elastic texture" of aerated bread; and secondly, to provide mechan ical means for dividing the dough into the requisite exact and uniform measured quantities for loaves, and for delivering each loaf into the tin in which it is to he baked. Dr. Dauglish's last patent—his new mechanical or traveling oven—was only completed shortly before his death, winch took place in the spring of 1863. In
this oven, the loaves, after being placed on the movable bottom at the mouth, arc carried with a regular intermittent motion, in an endless chain, whieh forms the movable bottom, through a chamber varying in length from 20 t) 5d ft., to the end or tail of the oven. This chamber is heated by two or more furnaces, the tines of which are kept separate, each furnace heating its own portion. Small windows are inserted at intervals, by means of which the baking can be watched during its progress. The month of the oven is protected by two doors, which are lifted and shut alternately by an arrangement of apparatus worked by the same power which causes the endless chain constituting time movable bottom to traverse the length of the oven; the work of charging the oven !goes on incessantly while the loaves are on their journey toward the tail of the oven; and the opening and shutting of the two oven doors is so arranged as to prevent the escape of the heat or steam from the interior of the oven. On the arrival of the loaves at the tail of the oven, the baking process is completed, and they are tipped off the revolving bottom, falling, by their own weight, on to a table placed ready to receive them. The mechanism at the tail of the oven is likewise so arranged as to prevent the escape of the heat or steam in the By means of this traveling oven, time old and laborious plan of putting into and taking out of the oven each loaf separately with the peel (so injurious to the health of the jonrneyman baker) is henceforth abolished in the making of aerated bread. The great point mentioned above, namely. lessening, the amount of pressure brought to bear on the gas, had its value fully borne out by recent experience. At present (1819) 90 lbs. pressure per square inch has been lessened to 30 lbs., to the saving of steam-power, and improving the quality of the bread. The Americans have tried an enormous pressure, but, we believe, without satisfactory results.