our uniformly recommending
the fixed roof principle. Now, for the purposes of the florist or
nurseryman, I think there is but little doubt that the advantage is with
the sash over the fixed roof. The difference in cost is trifling;
probably a little in favor of the fixed roof; but balanced against that
is, that your house, once erected on your favorite plan, you are
emphatically "fixed." It is not portable, (unless made in sections,
which is only a bad compromise with the sash plan,) and any alteration
requiring to be made, your roof is of but little or no value. But the
most serious objection to it is the difficulty with air. I have never
yet seen a house built on the fixed roof principle that had means of
giving air so that plants could be grown in a proper manner, and I could
name dozens who have been induced to build on this plan, that one year's
experience has given them much reason to regret.

[Illustration: FIG. 4. _a, ground level.--b, bench or table on which to
stand plants, 4-1/2 feet wide.--c, 4 inch pipe, 3 in each house.--d,
pathway, 2 feet wide._]

We are now adopting for plant houses, low, narrow, span-roofed
buildings, formed by 6 feet sashes, one on each side, the _ends_ of the
houses facing north and south. These we attach three together, on the
"ridge and furrow" system, as shown in sketch. This system presents
great advantages, and, by using no cap on the ridge piece, air is given
in the simplest and safest manner, by the sash being raised by an iron
bar 9 or 10 inches long, pierced with holes, which answers the double
purpose of giving air and securing the sash, when closed, from being
blown off by heavy winds. There is no necessity for the sashes being
hinged at the bottom, as might be supposed; all that is required being
to nail a cleet along the wall plate, fitted tight to the bottom of each
sash. Every alternate sash is nailed down; the other is used in giving
air in the manner described.

The advantages of such erections are so obvious, that I need not
trespass much on your space to enumerate them. The plan can be adapted
to detached buildings already up, by erecting houses of the same length
alongside; or, in the erection of new houses, if not more than one is
wanted, it may be put up with a view to further extensions. I have had
four houses on this plan in operation for nearly two years, and I have
never before had so much satisfaction with any thing of the kind.
Intending next season to r