el2 FEDERAL REFOBTEB. �the invention is one of "improvements iu air-heating fur- naces." The right figures in the drawings are all of them views of different parts of a furnace. The specification says : "My said invention consista of several improvements in hot- air furnaces designed to be set in brick-work or inclosed in any suitable manner." �The specification then divides the invention into six parts. The first part consista of one particular; the second part of three particulars; the third part of one particular; the fourth part of two particulars ; the fifth part of one particular ; and the sixth part of one particular. There are as many claims asthere are particulars, namely, nine. Only the second and third claims are involved in this suit. They relate to partic- ulars 1 and 2 of the second part of the invention. �The text of the specification says, in respect to those par-
- '"ulars : "My invention also consists in the eombination and
arrangement of a passage way from and through the furnace iront to and into the fire-pot at the bottom thereof, the pas- sage way being of sufiicient width and height to admit of the intraduction of a slioer or poker for the purpose of slicing the fire and removing the clinkers from the grate-bars foi'ward; the bottom of the passage way being on a line with the top suiface of the grate bars, and the top and sides of the passage ■way being formed by an enclosing plate, extending from the fire-pot to the furnace front, and joining at the sides the ash pit box, 80 as to prevent any communication between said passage way leading from the furnace front into the fire-pot and the hot-air chamber surrounding the fire-pot ; and this part of my invention further consists in combining with said enclosed passage from the furnace front to the fire-pot a dowuward openiag between the furnace front and fire-pot, leading from said enclosed passage to the ash pit, whereby clinkers and other matter removed from the fire-pot may fall into the ash pit." �The specification also says: "The drawings illustrate a funiace for brick-work, in which my inventions are embodied. The iire-pot a is a cylindrical casting, such as commonly used for that purpose, and sets upon a box, also of cast-iron, which ��� �