118

DESCRIPTION OF THE

without admitting air into the vessel by the stop-cock and bent tube, exhibited in the figure.

The shorter pipe N, which proceeds from the tarcistern, fig. 3, plate II., and communicates with thepurifying apparatus or lime machine, fig. 2, plateII., serves to convey the gaseous fluid, which accom-panied the condensible liquids deposited in thetar cistern, back again into the lime machine,or purifying apparatus, fig. 2, plate II., the con-struction of w hich, together with the conveyanceof the gas from this vessel to its place of destinationwill be stated hereafter.

L, fig. 1, plate II., or fig. 2, plate VII., isan iron flap table, placed level with the bottom ofthe mouth of the retort. It is convenient to holdseveral coal trays ready charged w ith coal in a statefit to be introduced into the retort.

The fire-place, flues, and ash-pit of the furnace,in w hich the retort is fixed, are sufficiently obviousby mere inspection of fig. 1, plate II. The frontelevation of the retort is seen in fig. 2, plateVII., which exhibits three horizontal retorts ; twoof which have the door of the mouth-piece slided