mited
surface of piping generally employed in heating plant structures; what is
thought to be just enough to maintain a given temperature, is usually
after minute calculation, the quantity which is made use of, and the
consequence is, that under adverse circumstances, the apparatus is
necessarily worked at its highest pitch; and I believe that the
application of heat in this form, whether it be by means of an hot water
apparatus, or by a common flue, is most inimical to the plants submitted
thereto. The admission of air, is a point which as far as I am aware, has
never been effected in the manner represented in the sketch: it would be
thus effected;--a series of apertures (_f_) should be provided at
intervals along the front wall, which would externally be closed by small
sliding shutters, and would communicate internally with a chamber (_g_)
formed between the front wall and the side of the tank; this chamber would
also communicate, by a series of openings, (_h_) with the interior space
above the water in the tank, and from this space, through the covering of
the tank, tubes (_m_), also placed at intervals, would be carried up
through the soil, close to the side of the wall; these tubes should be
furnished with caps or valves, so as so admit of the communication being
stopped at any time. In applying this to the admission of air, we must not
loose sight of a series of ventilators, (_i_), placed in the back wall of
the house, which are of precisely the same nature and construction as the
apertures (_f_), already spoken of. I shall have occasion hereafter, to
notice the admission of air, but it will be well in this place, to explain
the action of the plan proposed for that purpose: when it is judged that a
change of the internal volume of air is requisite, the ventilators (_i_)
are to be opened, which admits of a portion of the rarified air to pass
off; the ventilators (_f_) are also to be opened, and by means of the
action of these ventilators on each other, a portion of external air is
taken in; this enters the chamber (_g_), which is warmed by its contiguity
to the tank, and here becomes partially rarified, and rises to the top of
the chamber; the apertures (_h_) admit it to the interior of the tank,
where it becomes not only thoroughly warmed, but also imbibes a degree of
moisture proportionate to the degree in which it becomes heated, and
thence it enters the house by the tubes or shafts already spoken of. The
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