The great difficulty attending the successful burning of such refuse fuel as cannot be burned on a grate but has to be consumed on a hearth, is to introduce sufficient air into the material as will supply oxygen enough to consume all the carbon of the substance. The furnace represented in our illustrations is intended to overcome this difficulty; and the peculiar construction of it for this purpose will be understood from the following description. Fig. 1 is a sectional elevation of the furnace, and Fig. 2 is a horizontal section. H is a cylindrical fire-place or furnace, having vertical sides up to a certain point, from which rises a dome-shaped top. From the cylindrical furnace a number of angular projections, B', are built inside, and through these passes the air conduit or space, G, communicating with the external air, as seen in Fig. 1. This is divided into three draft passages, CCB, as seen in Fig. 2, and thus supplies air at three different portions of each angular projection. To each of the passages, G, there is a damper, g, which enables the air to be supplied into the center of a cone, E, , and from that to be distributed by four draft or supply passages, E', right into the center of the burning mass. There are a series of j openings in the furnace wall, A, which can ii be closed with doors, and are used for looking ' c into the furnace to see how the operation is gggoing on. There are also opeuings for clean- ing the hearth of the furnace and exhausting the ashes. On a support, a, rests the boiler, and under it the heated products of combustion pass, giving up their heat to it on their way to the chimney, F. There is a transverse bridge, 5, in the flue, and some side bridges e', are erected on an arch that crosses the flue, so dividing the flue into two parts horizontally, d being the lower passage. The operation is as follows:—The fuel being fed through the hopper, I, by means of a feeder, J, and the fife lighted, the external air coming through the passages, G, becomes heated, and so is admitted to the fuel at a temperature conducive to promoting combus- tion, and besides it being admitted in so many places, every portion of the fuel has a chance of being burned. The heated products of combustion pass through the flue, D, and over the bridge, J, giving up their heat to the boiler, and also in the direction of the arrows in Fig. 2, around the side bridges, e', so that no heat may be lost. There is a damper,/; at the side of the chimney, which directs the gases through the side bridges, e', or under them, through the passage, d, into the chimney, F. This is an excellently contrived furnace, and is the invention of Evan Skelly, of Pla-quemine, IberviUe Parish, La. He has applied for a patent, and will be happy to give any further information upon being addressed as above.