, DESCRIPTION or a 
thought of any improvement it may be capable of, though 
fuch may occur to others. For common ufe, while in 
France, I have contrived another grate for coals, which has 
in part the fame property of burning the {moke and pre- 
ferving the red coals longer by the flame, though not fo 
completely, as in the vafe, yet fufficiently to be very 
ufeful, which I fhall now defcribe as follows. 
A, is a round grate, one foot (French) in dia- omer 
meter, and eight inches deep between the bars and 
the back; the fides and back of plate iron; the fides hav- 
ing holes of half an inch diameter diftant 3 or 4 inches from 
each other, to let in air for enlivening the fire. The back 
without holes. The fides donot meet at top nor at bot- 
tom by eight inches: that fquare is filled by grates of {mall - 
bars croffing front to back to let in air below, and let out 
the fmoke or flame above. The three middle bars of the 
front grate are fixed, the upper and lower may be taken 
out and put in at pleafure, when hot, with a pair of pincers. 
This round grate turns upon an axis, fupported by the 
crotchet B, the ftem of which is an inverted conical tube 
five inches deep, which comes on as many inches upon a 
pin that fits it, and which is fixed upright in a caft iron 
plate D, that lies upon the hearth; in the middle of the top 
and bottom grates are fixed {mall upright pieces E E about 
an inch high, which as the whole is turned on its axis ftop 
it when the grate is perpendicular. Figure 1g is another 
view of the fame machine. 
In making the firft fire in a morning with this grate, 
there is nothing particular to be obferved. It is made as 
in other grates, the coals being put in above, after taking 
out the upper bar, and replacing it when they arein. The 
round figure of the fire when thoroughly kindled is agree- 
able, it reprefents the great giver of warmth to our fyftem. 
As it burns down and leaves a vacancy above, which you 
would fill with frefh coals, the upper bar is to be taken 
out, and afterwards replaced. ‘The frefh coals while the 
grate 
