intered at the Post Office at Philadelphia in accordance with Section 199 of the Postal Laws and Regulations. Report of the Committee on Science and the Arts. MacCoy's Pneumatic Tool, Blindness and the Blind (Concluded). By L. Webster Fox, M.D., Harbor Bar Improvements. By L. M. Haupt, C.E., Cable Telegraphy.-Delany Line Adjuster. By Patrick Bernard Delany. HOWSON AND HOWSON COUNSELLORS AT LAW SOLICITORS OF PATENTS PHILADELPHIA Forrest Building, 119 South Fourth Street NEW YORK Potter Building, 38 Park Row WASHINGTON Atlantic Building, 928 F Street THE JAMES SMITH WOOLEN MACHINERY COMPANY, Works, 411 to 421 Race St., Philadelphia, Pa. WOOLEN MACHINERY, Including Machinery for the Preparation of Wool. ALSO CARD CLOTHING OF EVERY DESCRIPTION. SEND FOR ILLUSTRATED CIRCULARS. BORGNER & O'BRIEN 23o ST. ABOVE RACE PHILADA PA FIRE BRICK THE FRANKLIN INSTITUTE is not responsible for the statements and opinions advanced by contributors to the JOURNAL. MACCOY'S PNEUMATIC TOOL. [Report of the Committee on Science and the Arts.] [No. 1478.] HALL OF THE FRANKLIN INSTITUTE, PHILADELPHIA, May 28, 1889. The Sub-Committee of the Committee on Science and the Arts, constituted by the FRANKLIN INSTITUTE of the State of Pennsylvania, to whom was referred, for examination, MACCOY'S PNEUMATIC TOOL. Report that: This invention consists in an automatic hammer reciprocated in a cylinder by compressed air or by steam, and delivering a rapid succession of blows upon a tool-holder, into which are inserted suitable bits or chisels for cutting wood, metal or stone; and embraces in its details valves for admitting and exhausting the air, a provision for relieving the cylinder and piston from injurious friction and for cushioning the piston and holding the bit-socket in posiWHOLE NO. VOL. CXXVIII. (THIRD SERIES, Vol. xcviii.) tion to facilitate its easy and steady application to the work. As exhibited to the committee, it was working at a very high speed, from the pitch of the sound probably more than five thousand strokes per minute. (Figs. 1−7.) The instrument, as complete and connected ready for action, appears in the form of a short cylinder, having a flexible tube centrally connected to one end, through which compressed air or steam is supplied at a pressure of about forty pounds per square inch, and centrally at the other end, a guide or sleeve, in which the tool-holder reciprocates; into the socket of the tool-holder the cutting bits, chisels or hammers are inserted. Upon disengaging a latch by pressing a button, the ends of the cylindrical case can be unscrewed, and inside of the shell or cover is found a working cylinder, with grooves on its outer surface and passages leading from the flexible tube at the centre of the upper cylinder head to one slotted chamber in the outside of the working cylinder and terminating in inlet ports leading into the interior of the working cylinder. Another slotted chamber in the external surface of the working cylinder leads from reduction ports through the cylinder and terminates in a channel leading to the atmos phere through the head of the cylinder. The piston is made long and fits fluid-tight, but with a minimum of friction in the cylinder. In the piston, but working transversely through it, is a piston valve which is worked by the pressure of air admitted through the port in the side of the cylinder and exhausted through other ports in the same manner as the piston valves of some steam pumps, the proper ports in the cylinder being covered and uncovered by the motion of the piston. The valve consists of a cylindrical plug having two grooves formed therein with a collar between them, and fits in a cylindrical transverse seat in the piston and covers and uncovers, at proper intervals, admission and exhaust ports. leading to the ends of the working cylinder. The piston is not attached or connected to the toolholder, but strikes upon it as a ram or hammer; a spiral |