MOTT'S VENTILATING SCHOOL-STOVE, FOR BURNING WOOD OR COAL.

Patented and Manufactured by J. L. MOTT, 264 Water-street, N. Y.

By this stove the room is warmed by conducting a supply of moderatery heated pure air from without, as well as by direct radiation from the upper portion of the stove.

This, and all stoves designed to promote ventilation by introducing fresh air from without, will work satisfactorily only where a flue properly constructed is provided to carry off the air which has become impure from respiration.

CHILSON'S COAL VENTILATING SCHOOL STOVES.

The Boston Ventilating Stove, Fig. 1, designed and patented by Dr. Clark, and Chilson's Patent Trio Portable Furnace, Fig. 2, are composed of a cylinder of sheetiron, inclosing a fire-chamber which is lined with soapstone, or fire-brick, and is so made as to present a large amount of radiating surface. The air to be warmed, is introduced beneath the fire-chamber by a flue from out of doors, and passing up, and around the heated surface, flows directly into the room, or into pipes to be communicated into other departments, as indicated by the arrows in the above drawings. These stoves and furnaces are intended to burn coal.

Mr. Chilson has also patented a plan of stove for burning wood, Fig. 3, by which the air is introduced by a flue beneath the stove, and is warmed by circulating through cast-iron tubes, which constitute the sides and ends of the stove.

CHILSON'S AIR WARMING AND VENTILATING FURNACE.
Patented and Manufactured by Gardner Chilson, Boston.

The construction of the Air- Warming and Ventilating Furnace was projected by the inventor, to obviate the serious, if not fatal, objections, so generally made, to the use of furnaces for warming apartments, where a fresh, healthful atmospheric air is required. From long experience in putting up furnaces, in which coal was consumed in deep iron pots, and the air which they warmed was made to pass over a large extent of iron surface, made and kept red-hot, he found that the occupants of the rooms thus warmed, complained that the air was not unfrequently filled with the gases of the burning coal, and was at all times dry and stagnant, causing, especially to persons of a nervous temperament, disagreeable sensations to the whole system, such as dizziness of the head, headache, inflammation of the eyes and lungs, dryness of the lips and skin, &c. He found, too, by his own experience and observation in the manufacture and use of furnaces of this kind, that there was an unnecessary consumption of coal, when burnt in deep, straight and narrow pots, causing the coal to melt and run to cinders, and at the same time burning out the pots, and loosening the joints of the furnace, by which the deadly gases escaped into the air-chambers, and hence into the apartments above. These objections, both on the score of health and expense, the inventor claims that he has thoroughly obviated in his Air-Warming and Ventilating Furnace, and at the same time preserved all the advantages heretofore realized from this mode of warming buildings. The advantages of the Furnace are

1. The fire-pot is constructed on the most economical and philosophical principles. It is broad and shallow,-at least twice as broad and one third as deep as the common fire-pot;-is one third smaller at the bottom than at the top, and is lined with fire-brick or soap-stone. Thus the fire-bed is deep enough to keep the coal well ignited with a slow but perfect combustion, while the entire heat from the fuel is given out to act upon the radiating surface alone and the fire-pot can never become red-hot, and does not require renewal. This plan for burning coal is original with the inventor, and has met with universal approbation.

2. The radiating surface is large, and so placed that it receives the immediate and natural action of the heat, and at the same time imparts its heat in the

most direct and uniform manner to the fresh air from without, without suffering waste by absorption from the outer walls of the air-chamber.

3. The air-chamber is large, and the fresh air is admitted and discharged so readily and uniformly that no portion of the radiating surface can ever become overheated; and a delightful summer temperature is maintained in the

rooms.

4. The joints of the furnace are so constructed, that, even if the iron-work was liable, like other furnaces, to crack from extreme expansion, by being overheated, (which it is not,) the gas from the burning coal cannot escape into the air-chamber.

5. There are no horizontal inner surfaces on which dust and soot can gather, which do not, at the same time, clean themselves, or admit of being easily cleaned.

6. The grate in the fire-pot is so constructed, that the ashes can be easily detached, and the combustion facilitated.

7. It has stood all the test which sharp rivalry and the most severe philosophical practical science could apply to it, and has thus far accomplished all that its inventor promised, and when tried in the same building with other furnaces, has uniformly received the preference.

Dr. Bell, Superintendent of the McLean Asylum for the Insane, who has given this whole subject his particular attention, in his Essay on the Practical Methods of Ventilating Buildings, published in the proceedings of the Massachusetts Medical Society for 1848, remarks as follows:

The character of any variety of the hot-air furnace is measured, in my judgment, by the simplicity of its construction, its non-liability to be brought to an undue degree of heat in any part, and its ready receipt and emission of air. That made by Mr. Gardner Chilson, of Boston, with an air-chamber of brick, and an interspace of two or three feet in width, appears to me to combine all the essentials attainable of this mode of heating air, more fully than any other which has fallen under my observation."

In 1847, the School Committee of Boston sanctioned, by a unanimous vote, the introduction of this furnace into the new school-houses to be erected in that city, on the recommendation of a sub-committee, to which the whole subject of warming and ventilating the school-rooms had been referred. The following is the recommendation referred to.

"Your Committee have made themselves acquainted not only with all the Furnaces which have been manufactured in this place, and its neighborhood, but with all those which have been exhibited here recently. Most of them show much ingenuity of contrivance and excellence of workmanship; but are all, so far as we can judge, inferior, in many respects, to the one invented by Mr. Chilson, a model and plans of which we now exhibit, and recommend as superior to all others.

It is simple in its structure, easily managed, will consume the fuel perfectly, and with a moderate fire. It is fitted for wood or coal. The fire-place is broad and shallow, and is lined with soapstone or fire-brick, which not only makes it perfectly safe and durable, but modifies very materially the usual effect of the fire upon the iron pot.

The principal radiating surfaces are wrought iron, of a suitable thickness for service, while at the same time the heat of the smallest fire is communicated immediately to the air-chamber. The mode of setting this Furnace we consider essential; more especially the plan of admitting the air to the furnace at its lowest point, as it then rises naturally into the apartments above. This process cominences as soon as the temperature is raised even a single degree. The outer walls remain cold; the floor above is not endangered, and the whole building is rapidly filled with an atmosphere which is at once salubrious and delightful."

This Ventilating Furnace may be seen in the Mayhew, Dwight, Hancock, Boylston, Bowdoin, and Ingraham school-houses, in Boston; also in several new school-houses in Cambridge, Roxbury, Dorchester, Springfield, in the Blind Asvium and House of Industry, South Boston, and in hundreds of private houses in Eoston and its vicinity.