Fig. 2 shows the arrangement of the apparatus for the quantitative analysis of oxide of carbon and hydrogen by combustion. The gas in the burette is first mixed with atmospheric air, by allowing the liquid to flow through _b_, and causing air to enter through the axial aperture of the three way cock, _a_, after cutting off communication at v. Then, as shown in the figure, the burette is connected with the tube, B, which is filled with water up to the narrow curved part, and the interior of the burette is made to communicate with the combustion tube, v, by turning the cock, a. The combustion tube is heated by means of a Bunsen burner or alcohol lamp, L. It is necessary to proceed, so that all the water shall be driven from the cock and the capillary tube, and that it shall be sent into the burette. The combustion is effected by causing the mixture of gas to pass from the burette into the tube, B, through the tube, v, heated to redness, into which there passes a palladium wire. Water is allowed to flow through the point of the tube, B, while from the flask, F, it enters through the bottom into the burette, so as to drive out the gas. The water is allowed to rise into the burette as far as the cock, and the cocks, _b_ and _b¹_, are afterward closed.
By a contrary operation, the gas is made to pass from B into the burette. It is then allowed to cool, and, after the pressure has been established again, the contraction is measured. If the gas burned is hydrogen, the contraction multiplied by two-thirds gives the original volume of the hydrogen gas burned. If the gas burned is oxide of carbon, there forms an equal volume of carbonic acid, and the contraction is the half of CO. Thus, to analyze CO, a portion of the liquid is removed from the burette, then caustic potash is allowed to enter, and the process goes on as explained above.
The total contraction resulting from combustion and absorption, multiplied by two-thirds, gives the volume of the oxide of carbon.
The hydrogen and oxide carbon may thus be quantitatively analyzed together or separately.--_Revue Industrielle_.
The accompanying engravings illustrate a new and very simple form of gas engine, the invention of J. A. Ewins and H. Newman, and made by Mr. T. B. Barker, of Scholefield-street, Bloomsbury, Birmingham. It is known as the "Universal" engine, and is at present constructed in sizes varying from one-eighth horse-power--one man power--to one horse-power, though larger sizes are being made. The essentially new feature of the engine is, says the _Engineer_, the simple rotary ignition valve consisting of a ratchet plate or flat disk with a number of small radial slots which successively pass a small slot in the end of the cylinder, and through which the flame is drawn to ignite the charge. In our illustrations Fig. 1 is a side elevation; Fig. 2 an end view of same; Fig. 3 a plan; Fig. 4 is a sectional view of the chamber in which the gas and air are mixed, with the valves appertaining thereto; Fig. 5 is a detail view of the ratchet plate, with pawl and levers and valve gear shaft; Fig. 6 is a sectional view of a pump employed in some cases to circulate water through the jacket; Fig. 7 is a sectional view of arrangement for lighting, and ratchet plate, j, with central spindle and igniting apertures, and the spiral spring, k, and fly nut, showing the attachment to the end of the working cylinder, f1; b5, b5, bevel wheels driving the valve gear shaft; e, the valve gear driving shaft; e2, eccentric to drive pump; e³, eccentric or cam to drive exhaust valve; e4, crank to drive ratchet plate; e5, connecting rod to ratchet pawl; f, cylinder jacket; f1, internal or working cylinder; f2, back cylinder cover; g, igniting chamber; h, mixing chamber; h1, flap valve; h2, gas inlet valve, the motion of which is regulated by a governor; h3, gas inlet valve seat; h4, cover, also forming stop for gas inlet valve; h5, gas inlet pipe; h6, an inlet valve; h8, cover, also forming stop for air inlet valve; h9, inlet pipe for air with grating; i, exhaust chamber; i2, exhaust valve spindle; i7, exhaust pipe; j6, lighting aperture through cylinder end; l, igniting gas jet; m, regulating and stop valve for gas.