CHIMNEYS. 233 
England, which are made on purpofe, and which are put 
upon the tops of them; but this method by no means an- 
fwered. I then thought of contra@ing them below, but 
as the method of contracting them in front to the fize of 
a fmall coal-fire grate has an unfightly appearance, as it 
makes a difagreeable blowing like a furnace, and as it is 
the occafion of confuming a great deal of unneceffary 
fuel, the heat of which is immediately hurried up the 
chimney, I rejected this method, and determined to con- 
tract them above, a little out of fight. For this purpofe 
J threw an arch acrofs, and alfo drew them in at the fides.. 
This had fome effet, but as this contraétion was made 
rather fuddenly, and the fmoke, by ftriking againft the 
corners that were thereby occafioned, was apt to recoil, by 
which means fome part of it was thrown out into the 
room ; I determined to make the contraGtion more gra- 
dually, and therefore run it up at the back, where the 
depth of the chimney would admit of it, and alfo fhelving 
or floping in a conical kind of direction at the fides, as 
high as a man, ftanding upright, could conveniently reach, 
and by this means brought the cavity within the fpace of 
about twelve by fourteen or fixteen inches, which I found 
fufficiently large to admit a boy to go up and down to 
{weep the chimnies. This method I found to fucceed per- 
featly well, as to curing the chimneys of fmoking, and it 
had this good effect of making the rooms contiderably 
-warmer ;. and as this experiment fucceeded fo well, fince 
the only ufe of a chimney is to convey away the {moke, 
I determined to carry it ftill farther, in order to afcertain 
with precifion, how much {pace is abfolutely neceflary for 
that purpofe, becaufe all the reft that is fhut up, muft be 
fo much gained in warmth. Accordingly I laid a piece’ 
of flate acrofs the remaining aperture, removable at plea- 
fure, fo as to contract the fpace above two thirds, leaving 
about three inches by twelve remaining open; but this 
{pace, except when. the fire burnt remarkably clear, was 
{carcely 
