220 GREENHOUSE CONSTRUCTION AND HEATING. 
pipes or houses well with the apertures between the bars 
choked with dust, clinkers, etc. Some men will keep the 
front part of the fire clean enough, but the back is allowed 
to become blocked up with dust and rubbish, consequently 
only half to two-thirds of the full or proper amount of heat 
is obtained. To clean the bars properly, the fire should be 
pushed back and the front half of the bars thoroughly freed 
from dust and clinkers ; then draw all the fire forward, rake 
out every bit of dust, etc., from the back, right up to the 
bridge, or end, then push part of the fire back again, spread 
it out evenly, throw on a little fresh fuel all over, let it 
draw up bright, and then bank up as required. In order to 
secure the maximum heat this operation should be gone 
through twice every day—morning and evening—and I have 
known more than one case where it made all the difference 
between plenty of heat in the houses and little or none. 
The weather, as well as the direction of the wind, etc., 
must also be carefully watched, and the fire regulated 
accordingly. A strong fire when the sun is rising brightly 
after a cold night will usually do more harm than good, and 
is simply waste of fuel. In cold weather, always get a good 
fire and the houses warm towards evening, and bank up on 
a nice, bright, but rather low, fire, and hot pipes. Nearly all 
furnaces draw better with the wind some ways than others, 
so regulate the draught accordingly. 
