difflcnltlea various plans havo been resorted to, but the bert
means for overcoming them are thus described ; fix the tar
Bttpply tank aa near the furnace to be Bnpplied as convenient,
and one foot higliei than the tar-injector inlet A cock is
Bcrewed into the side of the tank, to which is attached a piece
of composition pipe |-inch in diameter, ten inehea'long. To
this a i -inch iron service pipe is connected, the other end of
which ia joined to the injector. By these means it is found
that at the ordinary teraperaturp i-f the tar well (cold weather
excepted) ioar gallons of taj pei hour are delivered in a con-
stant steam into the furnace. If more tar is reo,nired, the piece
of |-inch tube must be shortened, or a larger tube Bubetituted,
and ji less tar is required it must bo lengthened. The risk of
stoppage in the nozzle ol the injector ts overcome by the steam
Jet, whicb scatters the tar into spray and thus ieeps eveijtiiing
clear. Troable being occasioned by the retorts becoming too
hot. in which case, on shutting off tho flow of tar for a while,
the tai in the pipe carbonized and caused a stoppage, a remov-
fcbla plug injector is fitted and ground in like the plug of a
cock, having inlets on citherside for tar and steam. This plug
Injector can be removed, the tar stopped in two seconds and
rcfixed In a similar time. The shell of the injector ia firmly
bolted to the top part of tho door frame. The door is swung
horizontally, having a rack in the form of a quadrant, by which
it is regulated to any required height, and to admit onj
quantity of air.
