_THE BUILDING IN ELEVATION._
“It is decided that we are to build our exterior walls with dressed
stone and range-work,” said Eugène, while they were levelling-up to the
ground-floor.
[Illustration: FIG. 30.]
“We have a good part of the materials on the ground. As regards
stones of large size, we shall get them from the quarries of Le
Blanc, which are only a mile or two distant. Our quoins, our door
and window-openings, our string-courses, cornices, dormer-windows,
and gable-copings, will be made of dressed stone. Let us begin with
the quoins. This is how you will give the details to Branchu; it is
a very simple matter. In this part of the country they sell stone by
the _scantling_; that is to say, the quarries supply it according to a
measure stipulated beforehand, and the price per cubic foot is less in
proportion to the uniformity of the order, and the ease with which it
is executed. Now our walls on the ground-floor are 2 feet thick: let
A be one of the corners (Fig. 30); for these you will require stones
all of the same scantling—2 ft 10 in. long by 2 feet wide, and a mean
height of 18 inches, which is the average thickness of the beds in the
quarries of this district. And these quoin stones will be placed as I
have marked here, one _a b c d_, the other _a e f g_, the result of
which will be that each stone will form alternately on one side and
the other a bond of 10 inches. The range-work having its courses about
6 inches thick, we shall have three courses of the range-work in the
height of each course of dressed stone, and the building as it rises
will present the appearance indicated by the perspective sketch B.
Between the plinth mould and the string-course of the first floor we
have 14 feet; nine courses of stone, plus the mortar beds, therefore,
will constitute its height. Let us see how we are to arrange our
window-casings. We must consider how to place the jalousies, which
cannot be dispensed with in the country, but which when folded back on
the face of the walls produce a disagreeable effect, very soon begin
to get out of repair, and are troublesome to shut or open, imposing
on the inmates of the dwelling a gymnastic exercise from which they
would gladly be excused. Interior reveals will be required sufficiently
deep for the casements, not to be flush with the walls, and to leave
a space between them and the curtains. Our widest windows are 4 feet
wide in the clear; our walls, on the ground-floor, are 2 feet thick;
we can therefore find a place for the jalousies in the casing, only
on condition of dividing each of these leaves into two or three folds.
Only those made of sheet iron will allow us to manage this, because
three sheets folded back on themselves are only 2 inches thick,
including the room left for the play of the hinges. This, then, is the
method given (in Fig. 31) of arranging the jambs of the windows: the
outside being at A, we will leave a thickness, B, to mask the leaves of
the jalousies folded up in the jamb of 4 inches. We will allow a space
of 10¾ inches for these leaves at C. Then will come the window-frame,
2¼ inches thick; total, 17 inches. We shall then have left 7 inches of
reveal inside at D.
[Illustration: FIG. 31.]
“You see at E how we shall build these window-openings: a sill, F,
of a single block of stone; then a course, G, 16 to 18 inches high,
bonding into the range-work; a stone on end, H, only the thickness of
the casing; a third course, I, like that marked G; and lastly, the
lintel. We will make this only the thickness of the casing, that is,
14¾ inches; we shall have left 9¼ inches, exactly space enough to turn
an arch of bricks, K (these being 9 inches long, and with the joint 9¼
inches). This arch will bear our joists, if there are any that have to
rest in the outer walls, and it will hinder a fracture of the lintels.
Besides this we will pass a tie-bar, L, under the latter. I find the
tie-bar more effective at this level than at the level of the flooring.
A tie-bar is an iron sinew placed in the thickness of the walls to bind
and keep in place the whole construction. It is not always placed in
houses built in country districts, but it is unwise to omit it—indeed,
a very poor economy to do so; for a building not tied is liable to be
easily cracked. But we shall speak of this again at the proper time.
Make a fair copy of these sketches and show them to me; and we will
give these details to Branchu.
[Illustration: FIG. 32.]
“We must also decide how we shall construct the floors. In Paris, at
the present day, they construct all the floors with joists of double T
iron, and for bearings of 16 to 20 feet they take iron 4½ to 6 inches
in vertical section. They pug these iron joists—placed about 28 inches
apart, and connected at intervals of about a yard, by iron tie-bars ⅝
in. square—with plaster concrete. This is no bad method, certainly;
but here we have neither the iron joists, which are so easily procured
at the great centres, nor the plaster-of-Paris, which is perhaps too
lavishly used in the capital, but which is nevertheless an excellent
material when it is properly employed, especially for the interior.
We must construct the floors with wood. But I have already told you
that timbers which have not been soaked for some time, and which have
been cut scarcely two years, decay very rapidly when enclosed, chiefly
in their bearings, that is their extremities built in the walls. To
prevent our floors giving us anxiety respecting their durability, we
must leave the timbers visible, and not build them in the walls. We
will, therefore, adopt the system of bearers attached to the walls to
receive the bearings of the joists; and as we have small oak trunks,
we will content ourselves with squaring them on two faces, and place
them diagonally, as I show you here (Fig. 32). For bearings of 16
to 20 feet, which are the largest we have, timbers 7 inches square
will be sufficient. If we think them insufficient we will put an
intermediate beam; that remains to be seen. These joists, diagonally
placed, present moreover their maximum of resistance to deflection.
We will place them at 20 inches from centre to centre. Their bearings
will be in the notches made in the bearers, as marked at A, and the
soffits—which are the spaces between the joists—will be made with
bricks placed flat-ways, overlaid with mortar and plastered beneath.
We may decorate these ceilings with line painting, which renders them
light and agreeable to the sight, as at H. Joists thus placed do not
present internal angles difficult to keep clean, and among which
spiders spin their webs. A dust with a soft brush readily cleans these
soffits.
[Illustration: FIG. 33.]
[Illustration: FIG. 34.]
“As to the bearers B, (placed against the wall, as section C
shows), they will be supported by corbels, D, a yard apart at most,
and by cramps, I, to prevent these timbers from giving out. This
arrangement will take the place of those cornices run in plaster,
which are of no use, and which we could not get executed properly in
this neighbourhood, where we have no good workmen in plaster. When
partitions above have to be supported, we will put a special joist,
the section of which I have sketched for you at E, composed of two
pieces, _a_ and _b_, with an iron plate between them—the whole fastened
together by iron pins at intervals. Joists like this are perfectly
rigid.
“As the joists rest on bearers, we have no need to trouble ourselves
about the windows, but we shall require trimmers at the chimney-breasts
and under the hearths, and—to receive these trimmers—trimmer-joists.
You will easily see that it would be dangerous to lay pieces of wood
under fireplaces. Accordingly, we place on the two sides of the jambs
of these fireplaces, at a distance of 12 inches from the hearth-stones,
stronger joists, which receive at 32 or 36 inches from the wall—to
clear the width of the fireplace—a piece called a trimmer, into which
the joists are tenoned.
“For the trimmer-joists we will take the type previously indicated at
E; we shall strengthen (Fig. 33) this beam in its bearing with a block,
D, resting on a strong stone corbel. We will bind the two pieces, E and
D, by an iron strap, F, and frame the trimmer by a tenon, H, in the
mortise G. This trimmer will receive, like the bearers, the ends of the
joists at I. The space, G K, will be the under side of the hearth of
the fireplace above; it will be 32 inches wide, and will be bedded with
brick, laid on tie-pieces of iron, L. These trimmer-joists, E, will
have to be let into the wall about 4 inches, to render them firm and
bind the structure; but in the neighbourhood of the flues we have no
reason to fear the effect of damp on the wood. To sum up, this is the
appearance of these joists and trimmers underneath the fireplaces (Fig.
34).”
All this, it must be confessed, appeared rather strange to Paul,
accustomed as he was to the invariable smooth white ceiling, and
who had never suspected that such level surfaces could hide such a
framework.