HORTICULTURAL JOURNAL. 133 
ON SUPPLYING HOTHOUSES WITH BOTTOM HEAT AND 
MOISTURE. 
Editor of the Florist. 
Every good gardener must know the value of bottom heat, and a means 
of supplying the atmosphere of his hothouse with moisture during the winter 
months in this climate, where the difference of temperature of the open air 
and his stove is such as the past winter has afforded a very striking example, 
is of paramount importance. Yet, how seldom are they employed : where 
flues are used as a means of heating, this cannot be done or at least s6 
readily, but with hot water, the reverse takes place, with a very simple con- 
trivance, both may be obtained at the same time. The following is the man- 
ner it has been employed here with perfect results, and although the house 
is a very lofty one for a stove, all above ground, and no means of using 
shutters except to the' front sash, the plants have retained a color of foliage, 
we are quite sure they would not, had it not been applied. A pit of 
four-inch brick work is built in the part of the house usually occupied 
by the back stage, two and a half feet high, having cross ties of wood built 
in at half its height to receive thick planking. Under this is a wooden 
tank with a division in its centre, and open at the end farthest from the 
boiler ; an inch lead pipe is carried from one side of this to the top of the 
boiler as supply, another from the other side to the bottom of the boiler as 
return pipe. The tank is partially covered with slate, a few openings being 
left for the vapor to pass out. The space above the planks is filled to the 
top with tan, in which the plants can be plunged, or stood on the top as the 
case may require. A few openings are left to the chamber below through 
the tan so that the moisture can pass freely out. Similar openings are also 
left in the bottom of the chamber, to cause the necessary current to carry 
out the liberated vapor. A very important feature in this arrangement is, 
that it is self-acting, that is, so far as moisture is concerned. The warmer 
the temperature out of doors, the less artificial heat is required in the house, 
and consequently less demand for moisture, and the amount of water evapo- 
rated is of course, in a ratio with its heat. Thus on one occasion, when the 
thermometer out of doors, registered 18 degrees below zero, the water was 
nearly on the boiling point, and the evaporation nearly steam ; but with such 
a drying heat as was then in force, (there being a flue as well as hot water), 
experience told me the atmosphere, or rather the plants needed all the mois- 
ture they could get, to prevent the supply coming from them, instead of 
their receivijig the benefits from it. Where obtainable, we prefer the tank 
