Also the plate, d, with its rectangular perforations and the gate or slide for clamping a single piece of weft projecting through the plate, substantially as shown and described. Also a mechanism substantially as set forth for "knocking off" the weft raising mechanism when a piece of weft is presented. 71,946.--BLACKBOARD FOR SCHOOLS.--William Arroquuier, Worcester, Mass. I claim covering the plaster, B, with a coating, C, composed of the ingredients named and applied in the manner above described whereby the proper color and roughness are obtained as set forth. 71,947.--MODE OF OPERATING SWELL IN MELODEONS.--C.E. Bacon [assignor to himself. George A Prince and Calvin F.S. Thomas], Buffalo, N.Y. I claim the arrangement of the swell pedals side by side with the bellows pedals and contiguous to and parallel therewith, for the purpose and substantially as described. 71,948.--MATERIALS FOR TRANSMITTING HEAT.--William C. Baker, New York city. I claim the employment of salted water, glycerin, or their equivalents, to prevent freezing in transmitting and diffusing heat through ordinary pipes, tubes or radiators for the purpose of warming and ventilating railroad cars, public vehicles and buildings, substantially as herein described. 71,949.--LAMP BURNER.--George E. Baldwin (assignor to E. Miller & Co.), West Meriden, Conn. I claim the arrangement of the auxiliary or ventilating tube, E, with the wick tube, B, combined with a solid partition, F, in the base of the burner so as to form a close chamber around the tubes and wick adjuster, substantially in the manner and for the purpose herein set forth. 71,950.--AUTOMATIC TOOTH PLUGGER.--Burr Bannister and George F. Green, Kalamazoo, Mich. We claim, 1st, The combination of an engine operated by means of compressed air with a tooth plugger for the purpose set forth and described. 2d, The lock, F, in connection with spring, 1, operated by cross head of piston rod, in the manner and for the purpose specified. 71,951.--CAR COUPLING.--William F. Barlow (assignor to himself, James Bower and W.A. Jackson), Monmouth, Ill. I claim, 1st, The catch, C, slotted draw head, A, and weight, X, combined as described and for the purpose set forth. 2d, The rods, M N and H, and elbow, K, combined as described and operating in combination with the elements of the first claim arranged substantially as described and for the purpose set forth. 3d, The weight, X, arranged as described for the purpose set forth. 71,952.--HARVESTER RAKE.--John Barnes, Rockford, Ill. I claim 1st, The inclined serrations, h h h, on the face of the rake head for the purpose of compacting the gavel. 2d, A compressor or supplementary rake pivoted to the rake handle and moving parallel to the rake head, substantially as described. 3d, The combination substantially as described of an automatic rake, a compresser and an interposed spring for the purpose set forth.