DIRECTIONS TO WORKMEN.

137

by a new one, because the preservation of the retortgreatly depends upon this precaution.

All the parts of the arms composing the move-able disc within the retort, may be taken out of thedoor of the retort, if they should rerpiire a repair,first taking off the cap from the perpendicular pipeE, fig. 1, plate II., surrounding the shaft of theretort, then the centre piece, or rose centre, F, fig.2, plate II., the shaft D, fig. 2, plate III., may bedrawn up through the pipe which surrounds it.

When the retort requires cleaning, which shouldbe done once every six or eight months, a screw maybe attached to the upper extremity of the shaft D,which passes through the retort; by this means, thearms and rose centre within the retort can easily beraised, to leave the bottom of the retort quite clear,in order that the lumps of coke, that may be scat-tered about, may be easily removed. And if anincrustation of coke should happen to be attachedto the bottom of the retort, it may be readily de-tached by a crow bar, or other suitable instrument.

The trays or coal boxes, fig. 12, plate II., may bemade by the stoker, of sheet iron, (called in com-merce No. 16,) framed upon a wooden mould madefor the purpose.