ents the
air from rushing upwards into the atmosphere of the house at this
point--in a sloping position, instead of a horizontal one.

The principle involved in the plan proposed for aeration or ventilation,
is no doubt a sound one; and though the plan which is more particularly
described may be modified and varied, yet it is believed to be efficient
for its intended purpose.

There can be no doubt that the admission of cold air to a structure in
which tender plants are being forced, either during winter or early
spring, is materially hurtful to the plants, in proportion to the
tenderness of their constitution; and the Cucumber being, under those
circumstances, a plant of a very tender and delicate nature, is especially
susceptible of harm from this source. As a consequence resulting from this
fact, there can be little hesitation in affirming that whatever fresh or
external air it may be necessary to admit, during the period referred to,
should be warmed before it reaches the plants, and in being warmed not
burned, but supplied with the additional moisture its increased heat
capacitates it to take up, and which, to be congenial to vegetation, it
requires. This is provided for by the plan already recommended, where the
cold air is made to pass through the tank containing the heated water
which warms the soil. By a perfectly practicable modification of this
arrangement, not only may this result be secured, but also the continual
circulation of the internal atmosphere may at pleasure be assisted and
accelerated, during the time when it might not be necessary to admit fresh
air. This would be an additional advantage. The arrangement proposed to
effect this, is to conduct the cold external air through a heated chamber
containing the tanks--these latter being covered, but also admitting of
being opened to any extent to supply moisture or steam in the proportion
required. The cold air, after passing upwards through the chamber, escapes
at the front of the house, and ascends to the upper part of the house,
from whence it finds its way downwards near the back wall, and there again
enters the chamber, through openings provided for the purpose. The
circulation of the internal atmosphere would be thus facilitated and
accelerated, even without the admission of any current of external air,
for, of course, there is more or less of this kind of movement going on in
the atmosphere, wherever and in whatever form a source of artificial he