ROOMS HEATED BY STEAM. main-pipe a declivity the other way, and allow all the water to collect in a hot well at the farther end, by means of a descending pipe, having a loaded valve at the end. This may be so contrived as to be close by the fire, where it would be so warm that it would not check the boiling if again poured into the boiler. But the utmost attention must be paid to cleanliness in the whole of this passage, because this water is boiled again, and its steam passes through the heart of every dish. This circumstance forbids us to return into the boiler what is condensed in the stew-pans. This would mix the tastes and flavours of every dish, and be very disagreeable. All this must remain in the bottom of each stew-pan; for which reason we put in the pipe rising up in the middle of the bottom. It might indeed be allowed to fall down into the stew-chest, and to be collected in a common receptacle, while the fat would float at top, and the clear gravy be obtained below, perhaps fit for many sauces.

The completest method for getting rid of this condensed steam would be to have a small pipe running along the under side of the main conductor, and communicating with it at different places, in a manner similar to the air discharge on the mains of water-pipes. In the paper manufactory mentioned above, each steambox has a pipe in its bottom, with a float-cock, by which the water is discharged; and the main pipe being of great diameter, and laid with a proper acclivity, the water runs back into the boiler.

But these precautions are of little moment in a steam-kitchen even for a great table; and for the general use of private families, would hurt the apparatus, by making it complex and of nice management. For a small family, the whole apparatus may be set on a table four feet long and two broad, which may be placed on casters, so as to be wheeled out of the way when not in use. If the main conductor be made of wood, or properly cased in flannel, it will condense so little steam that the cooking table may stand in the remotest corner of the kitchen without sensibly impairing its performance; and if the boiler be properly set up in a small furnace, and the flue made so that the flame may be applied to a great part of its surface, we are persuaded that three-fourths of the fuel used in common cookery will be saved. Its only inconvenience seems to be the indispensable necessity of the most anxious cleanliness in the whole apparatus. The most trifling neglect in this will destroy a whole dinner.

We had almost forgotten to observe, that the boiler must be furnished with a funnel for supplying it with water. This should pass through the top, and its pipe reach near to the bottom. It will be proper to have a cock on this funnel. There should also be another pipe in the top of the boiler, having a valve on the top. If this be loaded with a pound on every square inch, and the fire so regulated that steam may be observed to puff sometimes from this valve, we may be certain that it is passing through our dishes with sufficient rapidity; and if we shut the cock on the funnel, and load the valve a little more, we shall cause the steam to blow at the covers of the stew-pans. If one of these be made very tight, and have a hole also furnished with a loaded valve, this pan becomes a digester, and will dissolve bones, and do many things which are impracticable in the ordinary cookery.

Vol. XIX. Part II.

STEAM applied to Heating Rooms. Steam has been successfully applied as a substitute for open fires in heating manufactories, and promises to be highly beneficial, not only in point of economy in saving fuel, but also in lessening the danger of accidental fire. The following mode of heating a cotton mill by steam was proposed and practised in 1799 by Mr Niel Snodgrafs of Paisley. We shall give an account of it in his own words*.

"Fig. 1. presents a view of an inner gable, which is Mag. xxvii. at one extremity of the preparation and spinning rooms of the mill. On the other side of this gable there is a space of 17 feet, enclosed by an outer gable, and containing the water-wheel, the staircase, and small rooms for the accommodation of the work. In this space the furnace and boiler are placed on the ground. The boiler cannot be shown here, as it lies behind the gable exhibited; nor is it of any consequence, as there is nothing peculiar in it. It may be of any convenient form. The feeding apparatus, &c. are in every respect the same as in the boiler of a common steam-engine. A circular copper boiler, two feet diameter by two feet deep, containing 30 gallons of water, with a large copper head as a reservoir for the steam, was found to answer in the present instance. The steam is conveyed from the boiler through the gable, by the copper pipe B, into the tin pipe, C, C. From C it passes into the centres of the perpendicular pipes E, E, E, by the small bent copper tubes D, D, D. The pipes E, E, E, are connected under the garret floor by the tubes F, F, for the more easy circulation of the steam. The middle pipe, E, is carried through the garret floor, and communicates with a lying pipe, 36 feet in length (the end of which is seen at G), for heating the garret. At the further extremity of the pipe G, there is a valve falling inwards to prevent a vacuum being formed on the cooling of the apparatus; the consequence of which would be the crusting of the pipes by the preasure of the atmosphere. Similar valves K, K, are placed near the top of the perpendicular pipes, E, E; and from the middle one E, the small pipe passes through the roof, and is furnished with a valve at I, opening outwards, to suffer the air to escape while the pipes are filling with steam, or the steam itself to escape when the charge is too high.

"The water condensed in the perpendicular pipes E, E, E, trickles down their sides into the three funnels L, L, L, the necks of which may either pass through or round the pipe C, into the copper tube M, M, which also receives the water condensed in C, C, by means of the short tubes N, N. The pipe C, C, is itself so much inclined as to cause the water to run along it to the tubes N, N, and the pipe G in the garret has an inclination of 18 inches in its length, to bring the water condensed in it back to the middle pipe E. The tube M, M, carries back the water through the gable to the boiler, which stands five feet lower than this tube. It is material to return the water to the boiler, as, being nearly at a boiling heat, a considerable expence of fuel is thereby saved.

"The large pipes are ten inches in diameter, and are made of the second kind of tinned iron plates. The dimensions of the smaller tubes may be seen by their comparative size in the engraving, and perhaps they might be varied without inconvenience.

"The apparatus erected as here described, has been found sufficiently strong, and has required no material repairs repairs since the first alterations were made. The leading object in the instance under consideration being to save fuel, in order to derive as much heat as possible from a given quantity of fuel, the flue from the furnace, which heats the boiler, is conveyed into common flue pipes placed in the gable. These are erected so as to prevent any danger of fire, in the manner shown in the engraving, fig. 2. The steam with this auxiliary communicates a heat of about \(75^\circ\) to the mill, the rooms of which are 50 feet long, 32\(1/2\) feet wide, and 8\(1/2\) feet high, except the lower story and garret; the former of which is 11, and the latter seven feet high. The rooms warmed in this manner are much more wholesome and agreeable than those heated by the best constructed stoves, being perfectly free from vapour or contaminated air.

"The application of the principle to buildings already constructed, it is presumed, will be sufficiently obvious from the foregoing details. In new manufactories, where the mode of heating may be made a part of the original plan, a more convenient apparatus may be introduced. This will be best explained by a description of fig. 2, which gives a section of a cotton-mill constructed so as to apply the steam apparatus to a new building.

"The furnace for the boiler is shown at (fig. 2). The flue of the furnace conveys the smoke into the cast iron stove pipes, 1, 2, 3, 4. These pipes are placed in a space in the gable, entirely inclosed with brick, except at the small apertures, 5, 6, 7, 8. A current of air is admitted below at 9, and thrown into the rooms by those openings, after being heated by contact with the pipes. This part of the plan is adopted with a view to prevent, as much as possible, any of the heat, produced by the fuel used, from being thrown away. It may be omitted where any danger of fire is apprehended from it, and the smoke may be carried off in any way that is considered absolutely secure. So far, however, as appears from experience, there seems to be little or no danger of fire from a stove of this construction. The greatest inconvenience of a common stove is, that the cockle or metal furnace is liable to crack from the intensity of the heat. By the continuity of the metal from the fireplace, an intense heat is also conducted along the pipes, which exposes them to the same accident. Here the smoke being previously conveyed through a brick flue, can never communicate to the pipes a degree of heat sufficient to crack them. In like manner the pipes, having no communication with the rooms but by the small apertures, cannot come in contact with any combustible substance; and from being surrounded with air, which is constantly changing, can impart only a very moderate degree of heat to the walls. The iron supporters of the pipes may be imbedded in some substance which is a bad conductor of heat, as furnace ashes and lime, &c. The emission of heated air into the rooms may be regulated by valves. As the pipes are not exposed to cracking, there is no risk of their throwing smoke or vapour into the rooms.

"The boiler b, b, is six feet long, three and a half broad, and three feet deep. As there is nothing peculiar in the feeding apparatus, it is omitted. The boiler may be placed in any convenient situation. Where a steam engine is used for other purposes, the steam may be taken from its boiler. The pipe c, c, conveys the steam from the boiler to the first perpendicular pipe d, d, d, d. There is an expanding joint at e, stuffed, to make it steam-tight. The steam ascending in the first pipe d, d, d, enters the horizontal pipe f, f, f, f, (which is slightly inclined) expelling the air, which partly escapes by the valve g, and is partly forced into the other pipes. The valve g, being considerably loaded, forces the accumulating steam down into the rest of the pipes d, d, d. The air in these pipes recedes before the steam, and is forced through the tubes h, h, h, into the pipe m, m, m, whence it escapes at the valve i, and the syphon k. The water, condensed in the whole of the pipes, passes also through the tubes h, h, h, into the pipe m, m, m, which has such a declivity as to discharge the water at the syphon k, into the hot well n, whence it is pumped back into the boiler.

"The whole of the pipes are of cast iron, except m, m, m, which is of copper. The perpendicular pipes serve as pillars for supporting the beams of the house, by means of the projecting pieces o, o, o, which may be raised or lowered at pleasure by the wedges p, p, p. The pipes are sunk in the beams about an inch, and are made fast to them by the iron straps q, q. Those in the lower story rest on the stones s, s, s, s, and are made tight at the junction with stuffing. The pipe in each story supports the one in the story above by a stuffed joint as shown at r. The pipes in the lower story are seven inches in diameter; those in the higher six inches; those in the other two are of intermediate diameters. The thickness of the metal is three-eighths of an inch. The lower pipes are made larger than the upper, in order to expose a greater heated surface in the lower rooms, because the steam being thrown from above into all the pipes, except the first, would otherwise become incapable of imparting an equal heat as it descends. There is no necessity for valves opening inwards in this apparatus, the pipes being strong enough to resist the pressure of the atmosphere.

"The cotton mill is 60 feet long, 33 wide, and four stories high, the upper being a garret story. In the engraving, five parts out of nine in the length of the building are only shewn. The apparatus will heat the rooms to 85° in the coldest season. It is evident that, by increasing the size, or the number of the pipes, and the supply of steam, any degree of heat up to 212° may be easily produced. It may even be carried beyond that point by an apparatus strong enough to compress the steam: this, however, can seldom be wanted. At first it was objected to this construction, that the expansion of the pipes, when heated, might damage the building: but experience has proved, that the expansion occasioned by the heat of steam is quite insensible."

Steam has also been advantageously employed in drying muslin goods, when the state of the weather interrupts this process out of doors. This application of steam, we understand, was the invention of an ingenious mechanic in Paisley, who never derived the smallest benefit from the discovery. It was adopted immediately by some bleachers in the neighbourhood, and has now come into very general use. The steam is introduced into cylinders of tin plate, and the goods to be dried are wrapped round the cylinders which communicate to them a heat equal at least to the temperature of boiling water, and in this way the process of drying is expeditiously accomplished.