HORIZONTAL ROTARY RETORT.

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G, G, fig. 2, plate III.,# fixed in sockets made inthe box. These arms are elevated three inchesabove the bottom of the retort, and extend to nearlywithin its whole inner circumference. They arewedge-shaped, and their greatest diameter is at rightangles to the base of the retort, so that the weightof the arms rests on the axis. They are inter-sected by two concentric rings, as will be seen oninspecting fig. 5, plate III., which exhibits the planof the retort, together with the iron arms, G, G,and concentric rings. The centre of figure 5,shows also the plan of the rose centre F, fig. 2,plate III., into which the arms are keyed.

Betw een the arms are placed twelve shallow irontrays or boxes, destined to contain the coal fromwhich the gas is to be obtained. They are formedto the segment of a circle, hence the whole series ofthem when arranged in the retort, exhibits a shallowcircular tray, which, when motion is given tothe shaft, may be made to revolve within the retort.

* In the horizontal rotary Retorts at the Chester, Birmingham andBristol Gas Works, which are twelve feet six inches in diameter, thereare fifteen arms. At some Gas Works the arms are made of cast-iron,

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