The steam cylinder is secured in the middle of the base plate, and has the usual slide valve and piston, the latter being provided on each side with a hollow plunger which projects beyond the cylinder and is provided at its outer end with a cap. Near each cap is an adjustable ring, having a downwardly projecting forked lug sliding on a raised guide secured to the base. Into through it. This invention has been patented by Mr. C. K. McGehee, of Liberty, Miss. each of the hollow plungers projects a cylinder, held at one end in. the end plate, in which it communicates with the inlet and outlet valve, as shown in the sectional view. The inlet valves at each end lead to a channel in the base, in the center of which the inlet pipe is held ; and the outlet valves lead to a similar channel in the opposite side of the base, communicating with the discharge pipe, which is provided with an air chamber and check valve. The slide valve is so arranged as to be operated at each stroke by one of the rings secured to the ends of the plunger. The piston moves forward and backward, and imparts a reciprocating motion to the plungers, which slide over the stationary cylinders. This action draws water into the cylinders through the inlet valves and their channel, and discharges it on the return stroke through the outlet valves and their channel the boiler. The machine being double acting, a' constant flow of feed water is produced. The main frame, being in close con't itc t with the steam' cylinder, becomes heated, and consequently hea t s the water passing Steel Wire Gun. The Times states that the new experimental 9'2 in. wire gun has just been tried at the Government proof butts, Woolwich Arsenal, with satisfactory results. The War Department have issued orders for the construction of several more guns of the same description. The Government pressure test for the gun was 65 tons to the square inch. The new weapon weighs 25 tons, and is 33 ft. long. The steel wire is coiled round the inner tube at the breech and nearly up to the trunnions, and consists of 78 layers. The wire is made in lengths of 2,400 yards, and weighs 20 lb. to the yard. It is flat, and put on by a specially designed machine at a pressure of about 40 tons to the square inch. The lengths are joined together by being. brazed and riveted over a considerable length. After the wire has been put on,asteel jacket is shrunk on over it. Fireproofing and Preserving Compound. BY NOTZ&KONKAD. A solution is made of 10 kil. sulphate of ammonia, 1 kil. carbonate of ammonia, % kil. borax, 100 grin. bichloride of mercury in 30 lit. of water. To which solution the extract of 2 kil. peppermint is added, which is obtained by hot maceration of the herb in 6 lit. water ; then 150 grm. phenic acid are added, and lastly 6 kil. tungstate of soda diluted with 94 lit. water, in order to prevent the formation of crystals of the various salts and to maintain the fluidity of the chloride of lime which is formed. The whole is vigorously stirred, and heated to 70° C. At the same time, the communication is opened with a retort in which 1 kil. Peauvian balsam and 300 grm. camphor are distilled off in 2 kil. ether, and the distillate stirred The Wax Process tor Engraving. By means of the new and ingenious little instrument known as the hyalolypho-type, or hot pen, drawings can be made on glass or glassy substances with a waxy Transportlug Natural Gas. ColonelThomas P. Roberts, of Pittsburg, Pa.,ob-tained a patent for a process of transporting natural gas long distances, which he is confident overcomes all the difficulties resulting from friction and consequent loss of pressure. He proposes, instead of forcing the gas, to draw it at low pressure through large conduits by means of exhaust fans at distances varying from ten to forty miles, according to the - character of the ground to be traversed. These fans, which would be boxed into the conduit, would be about sixteen feet in diameter, and would be driven by engines of about twenty horse power. They would only revolve at the rate of from thirty to fifty times a minute—a slow rate as compared with the 2,000 revolutions a minute made by blast engine fans. The pipes would be made of sheet iron, about fi ve feet in diameter. The patent provides for an alternative method. This is to lay a second pipe under the other one when ascending a hill. This pipe is to be perforated with burners, the heat from which will rarefy the gas. At the top of the hill a tank of water will be placed, from which a. pipe would be laid over the gas pipe on the descent of the hill. This pipe also will be perforated to discharge a spray over the gas pipe, thus causing a condensation of the gas. This system will cause the main to act as a siphon, and will maintain an even flow over the hill. ___The jnajnfeature of this proceasJa. that the gas is allowed to flow at about or a little below nominal pressure, and' that thus the friction of the gas is reduced to almost nothing. The ' velocity of the ..gas would under this system, Colonel Roberts estimates, be not quiteten miles an hour, and the force.. required would be a small fraction of an ounce per square inch. The only leakage to be provided for would be the air trying to get into the pipe, and paint, Colonel Roberts says, would be ample to prevent this. The estimated cost of this method of transportation including fans, pipes, right of way, etc., would be about $3, and it would supply three million cubic feet of gas per hour.—The Coal Trade Journal. NEW POWER PUNCHING PRESS. The greatest length of Lake Michigan is 300 miles; its greatest breadth, 108 miles; mean depth, 690 feet; elevation, 506 feet; area, 23J000 square miles.
This article was originally published with the title "Boiler Feeder" in Scientific American 54, 26, 403 (June 1886)