HEATING BY HOT WATER. 219 
much stronger, as well as a very steady heat, lasting for 
many hours with little or no attention, and where it 
can be obtained at a moderate price—say anything under 
S1 per ton, delivered—it forms an on the whole cheaper 
and better fuel than coke—unless where this can be had 
very cheaply, say for anything less than 9s. or 10s. per 
chaldron of 386 bushels. This (anthracite) coal, in fact, 
must not be poked about much, or when hot it falls into 
small pieces, drops through the bars, and is wasted. A 
few fair to good-sized lumps thrown on a small but 
bright fire, and left alone, will burn steadily but surely 
out, and afford a strong and steady heat for several hours. 
It requires a rather sharper draught than coke, but this is 
easily afforded by slightly increasing the height of the 
chimney, and its use increases the heating power of a 
boiler by quite 20 or 30 per cent. over ordinary coke. 
Some growers use a mixture of coke and anthracite, 
and this undoubtedly gives a very strong heat, but with 
the disadvantage of burning both the bars and boiler 
through much more rapidly than either fuel alone. An 
excellent plan, however, is to use coke during the day, 
when less heat is usually required, and anthracite for 
making up the fires at night. Where this is done, and 
the furnace is large enough to contain a sufficient supply 
of fuel, the thermometer inside the house will be found 
very little, if any, lower at 6 or 7 a.m. than when the fire 
was made up at say 10 p.m. the previous evening. 
The main points to be observed in successful and 
economical stoking may be briefly summed up as follows :— 
Keep your fire-bars clean, and watch the weather. No fire 
can burn properly, or even if it does burn, cannot heat the 
