44 THE GRAPE. 
Boilers are made of several sizes, from those capable 
of heating a large grapery, down to those suited for 
small green-houses and plant-cabinets. 
Brick Flues—Heating by brick flues is often practised 
and if they be constructed on the best method, with good 
workmanship, they answer very well; the expense on 
first erection is less it is true, but they often want repair, 
besides which they are unsightly and cumbersome, and as 
a general thing, will consume more fuel than a hot-water 
boiler on the above plan. If the situation, or circum- 
stances, make it more convenient to burn wood instead of 
coal or coke, then the flue is to be preferred; in such case 
the furnace should be large, and the draft be under the 
control of the operator, by having a door in front of the 
ash-pit, and a damper in the chimney, which, when closed, 
more or less, as may be wished, will keep the tire steady. 
There are some cultivators who still cling to the flue for 
grape-growing, on account of the drying effects of the heat 
evolved, which, as they assert, is of some importance in 
damp weather, when the grapes are coloring, or ge and 
that at other times they can usc evaporating pans. ‘True, 
it is dry enough, even to parching; and were this the oy 
time when it would be required, th 
best - But this point is a matter of very little 
consideration, as the same can be secured by pipes heated _ 
with hot water. Nothing ean be more erroneous than to 
suppose that heat given out on the latter principle con- 
_tains moisture; were it so, the water would waste consid- 
erably through the pores of the metal, which is not the 
ease, for all or nearly the whole of the evaporation which 
takes place is at the filling up tank, and if this be kept 
covered, the working of a night will not lessen the water 
_ more than a few pints. Heat, from whatever sources ob- 
