The circle of the mechanical arts; containing practical treatises on the various manual arts, trades, and manufactures / By Thomas Martin.

  • Martin, Thomas (Civil engineer)
Date:
1813
Catalogue details

Licence: Public Domain Mark

Credit: The circle of the mechanical arts; containing practical treatises on the various manual arts, trades, and manufactures / By Thomas Martin. Source: Wellcome Collection.

    74/712 (page 60)
    in the coolers with the first wort, and when it is about blood warm, add four English quarts of yeast, to produce the fermentation, and after it has began to ferment the first time, (the froth running over into ! a receiver for the purpose,) throw it back again, and when it has fermented again, throw it back a second time, and it will after the third fermentation, be fit for use, as will be perceived by its being of the thickness that good yeast ought to be. Four bushels of malt, made in this way, produces about wenty-four quarts of yeast; it is an expensive and troublesome way of procuring it, but Mr. Giliispie finds, that a quart of it will go as far as a gallon of distillers yeast. DESCJII PTIOX OF TIIE R AKE HOUSE. The bake house is a manufactory where bread is made for sale. In order to render it convenient, it should be attached to the dwelling house, and have an inner door opening into the kitchen, and likewise an outer door opening into a small yard, in which there ought to be a well or pump, and also, a shed for piling away faggots. The room should be large and commodious, and the floor laid with stones or tiles. On one side should lie erected a dresser or counter, with suitable shelves about it; on another a kneading trough, about seven feet long, three feet high, two and a half broad at top, and sixteen inches at the bottom, with a sluice board to pen the dough up at one end, and a lid to shut down like that of a box'. On the third side a copper that will contain from three to four pails of water should be erected, which is far preferable to the filthy custom of heat- ing the water in the oven; and on the fourth side the oven should be placed. A bakehouse built upon this plan will, perhaps, be as commodious as art can render it ; but of late years, an alteration has been made in the maimer of fitting up the oven and copper, that both may be heated with the same fire. In order to comprehend the usefulness of this im- provement, it will be necessary to state that an oven, | built upon the old principle, is usually of an oval shape ; the sides and bottom of brick, tiles, and lime, and arched over at top with a door in front ; and, at the upper part, an enclosed closet with an iron grating, for the tins to stand on, called the proving oven. To heat these ovens, the faggots are introduced and burnt to an ash ; it is then removed, and the bottom cleaned out. This takes up a con- siderable space of time, during which period a great deal of heat escapes. A still farther length of time is necessary for putting in the bread, and unless much more fuel is expended than is really necessary, in heating an oven upon this principle, it gets chilled before the loaves ere all set in, and the bread is, therefore, liable to fall ; a circumstance that una- voidably renders it heavy. To remedy this inconvenience, many intelligent bakers have, within these few years past, had their evens built upon a solid base of brick and lime, with .st door of iron, furnished with a damper to carry off’ the steam as it rises. 0n one side of it is placed a fire with a grating, ash-hole, and iron door, similar to that under a copper, with a partition to separate it from the oven, and open at one end. Over this is erected a middling-sized copper with a cock at the bottom, and on one side of it is placed the proving oven ; the whole being faced with brick and plaster. When this oven is required to be heated, the copper is filled with water, and the fire being kindled w ith coals, the flame runs round the oven, in a circular direction, and renders it as hot as if heated with wood, without occasioning the least dirt or ill smell ; and the smoke escapes through an aperture, which passes into the kitchen chimney. When the coal is burnt to a cinder, there is no ne- cessity to remove it, as it prevents the oveu from cooling while the bread is setting in, and keeps up a regular heat till the door is closed. The advan- tages ofan oven built upon this construction, are so considerable, independent of the great saving in fuel, that when its principles come to be generally known amongst bakers, there is no doubt but that they will prefer it to those heated w ith wood. In great bakehouses, where rolls and French bread are wanted every half hour, from eight o’clock in the morning till eleven, the perpetual oven invented by Count Rumford, will be found particularly use- ful; more especially if they are called, upon to bake meat, puddings, and pies, at different hours in the af- ternoon. At present, after they are done, they are obliged to keep them warm in the proving oven; but the crust ahvays becomes heavy, and the meat sod- dened: but in one of these perpetual ovens, they might have such things baked, at the time their cus- tomers required them, without putting themselves to any material inconvenience, and besides, there would be this farther advantage attending the bak- ing, that the effluvia arising from the different sorts of meal would never be mixed, and occasion an ill | taste, as it now does in the great ovens. The follow- ing is the description given of it by the Count, with the manner of using it. In the centre of a circular, or, rather, a cylindrical mass of brick work, about eight feet in diameter, which occupies the middle of a large room on the ground floor, 1 constructed a small, circular, closed fire place, for burning either wood, coals, turf, or peat. The diameter of the fire place is about eleven inches; the grate being placed about ten inches above the floor, and the top of the fire place contract- ed to about four inches. Immediately above this narrow' throat six separate canals (each furnished w ith a damper, by means of which its opening can be contracted more or less, or entirely closed), go off horizontally, by which the flame is conducted in- to six separate sets of flues, under six large plates of cast iron, which formed the bottom of six ovens on the same level, and joining each other by their sides, which are concealed in the cylindrical mass of brick work. Each of these plates of cast iron, being in