448 
REGULARITY OF HEAT AND ECONOMY OF FUEL. 
tinues till the coal is perfectly coked. When a supply is required, 
fresh coal is placed in the feeder, and thrust on by the screw and 
box, which thus pushes forward the coke on the plane, till it falls on 
the grate, and then serves to distil and coke the new quantity. 
It is evident that the advantages of this new furnace are very great, 
as the numerous testimonials forwarded to us by Mr. Chanter, the 
present proprietor, abundantly prove, and to which we may append 
our own experience, having erected some at Chatsworth. The com¬ 
mand of heat is much greater, with less trouble, and the annoyance 
from smoke, for the most part, is removed. Mr. Wilmot, of Isle- 
worth, in writing on the advantages derived from some which he has 
had erected, says, “ After three months trial, I can now give you an 
account of the difference between your gas furnace, and those on the 
old principle: the former has that decided preference, that it only 
requires to be made known to be universally adopted. I put the 
lights on two vineries, sixty feet long (each), heated by hot water, 
on the 10th of January; the houses joining each other with a glass 
partition between, the boilers and pipes both of the same construc¬ 
tion : as such we started fair. The result is, that from that time 
until this date, April 13, 1833, the gas furnace is one month earlier 
than the old on?, and both houses have as good a crop of grapes as I 
ever saw grow. In February, I put the lights on two more vineries, 
of the same construction, but heated with flues instead of hot water; 
one is worked with the old furnace, and the other with yours. 
Yours has again the preference of nearly one month ; and I have no 
doubt I shall cut grapes in it a month earlier than in the old one, 
and both houses have as good as I ever wish to have. The one I 
have attached to a pine-house is certainly in the same proportions, 
hut the smaller one you last sent me to try the experiment exceeds 
all. It is under a small boiler which works from three-inch pipes, 
in a house put up on purpose; and although but eight inches, I con¬ 
sider it capable of heating any house, provided it he worked with hot 
water pipes. The use of the gas furnace is the greatest saving that 
can possibly be invented, not only in the consumption of fuel, but of 
the labour , while the uncertainty attending the old furnaces is en¬ 
tirely obviated, and one person can attend to twenty of yours, with 
more ease to himself, than to four of the old ones. The certainty of 
being able to leave it twelve hours in early firing , without finding 
any material difference in the thermometer, speaks more for this 
valuable discovery than if I were to write a volume on the subject.” 
Mr. M’c Intosh, gardener at Claremont, writes as follows : “ The eco¬ 
nomy in fuel is more than one-third, nearly one-half. The trouble of 
