_PAUL PURSUES A COURSE OF STUDY IN PRACTICAL ARCHITECTURE._
Meantime, letters and newspapers were daily bringing the most
distressing intelligence. The enemy had crossed the French boundary
a week ago. Building was a matter scarcely to be thought of. M. de
Gandelau was visited almost incessantly by country people coming to
impart to him their fears and to ask his advice. The able-bodied youths
of the district were summoned to be incorporated in the _mobile_.
The manufactories of the neighbourhood were being closed for want of
hands. Groups of peasants—men and women—might be met on the roads,
who, contrary to the quiet habits of this province, were speaking in
excited tones; some of the women were crying. The labours of the fields
were suspended; a painful shudder seemed to pass through the country;
lights were seen in the cottages at a late hour of the night; voices
were heard calling to each other. The cattle were brought in earlier
than usual, and were driven afield later in the morning. When people
met each other on the roads they would stay long talking. Sometimes,
instead of returning to their own abodes, they would walk rapidly on
together in the direction of the neighbouring town.
It was the 20th of August, 1870, when, going into his father’s room
early in the morning, Paul found him still more depressed than on
the previous days and it was not merely his aggravated gout that
caused the depression. Eugène was there.—“Some are too old, others too
young. If this boy was four or five years older,” said M. de Gandelau,
embracing his son, “I would send him with all these young fellows who
are summoned to the service; but he is too young, happily for his
mother. It will be a long struggle, they say; God only knows what will
become of our poor country engaged in an insensate war; but our duty
is clear—to remain here among all these families, distressed as they
are, and bereaved of their children; to wait, and try to calm down this
distracted multitude. Do not let us surrender our self-possession, or
give way to useless disquietude; let us work—that is the remedy for all
evils; and misfortune will not find us more destitute of courage after
days of labour than after a period of feverish inactivity. I see that
Paul will not be able to return so soon to college. As to yourself,
Eugène, nothing obliges you just now to stay in one place rather than
another. Your business will be suspended in every quarter; remain here,
where you can make yourself useful as long as the country does not
require your services.
“Who knows what may happen! But even if this state of things continues,
we will try to build Marie’s house; it will give employment to those
who have been thrown out of work. You will be able to give Paul
practical lessons in the elements of construction. We shall, perhaps,
run short of the one thing needful for building—money. Ah, well! that
will oblige us to discover the means of doing without it. We have
the raw material; we have hands, and enough to keep them for some
time to come. Let us, then, not give way to despondency and useless
recriminations; let us work; we shall be only the better prepared if in
one last effort we have to call upon all—old men and children with the
rest—to defend our native soil.”
Madame de Gandelau uniting her entreaties with those of her husband,
it was not difficult to persuade Eugène to take up his quarters at the
_château_. In fact, three days subsequently, after having gone away
to settle some affairs, he was on his way back with an ample store of
paper and instruments required for the details of a building plan.
They could not set to work till the sketch sent to Paul’s sister should
be returned, approved or amended. It was decided that during the
interval Eugène should give Paul the first notions of the building of
a house, that the morning should be the time for instruction, and that
in the afternoon our architectural tyro should reproduce the lesson in
writing, and have his work corrected at the family gatherings in the
evening. Thus the days would be well occupied.
LESSON THE FIRST.
“If you please, Paul, we will take our lessons walking, and for a good
reason.”
This arrangement was quite satisfactory to Paul, who was certainly not
accustomed to this mode of teaching at the Lyceum. The prospect of a
course of lessons delivered, re-produced in writing by the pupil, and
corrected _indoors_, had not seemed to him at the first blush quite
to harmonize with the idea which a youth of sixteen forms of hours
consecrated to recreation; and although after his first attempts
architecture seemed to him a very noble study, and he was proud enough
to think that _his plan_ was perhaps at this moment being inspected by
his sister Marie and her husband, yet, at the moment he was directing
his steps towards his cousin’s apartment, he had looked with a somewhat
longing eye at the fine old trees in the park, and the brilliant green
of the meadows between their dark trunks. A sigh of satisfaction
escaped him as he tripped down the steps.
“Let us proceed leisurely towards that part of the estate where we are
to build the house,” said his cousin, as soon as they were outside;
“a knowledge of the ground is indispensable to the architect’s
further progress. There are, as you know, several kinds of soils;
some resisting, others soft and compressible in various degrees.
Rocks form the firmest foundation—one on which we may build with
confidence—provided they have not been excavated or disturbed. The
name of _virgin soil_ is given to that which presents itself in the
condition in which geological phenomena have placed it; that of ‘made
ground’ to soil which has been disturbed or deposited by man, or
produced by vegetation, or brought to the spot by the sudden violence
of torrents. As a general rule, we should give an exclusive preference
to virgin soils; yet even some of these must be mistrusted, as I shall
explain to you directly.
“We must then endeavour to distinguish a virgin soil from ‘made’ or
disturbed ground; and to do so, some acquaintance with elementary
geology is indispensable. Thus, the crystalliform rocks, granites,
gneiss, and crystalline schists remain in the condition in which
the cooling of the globe and the upheavals of its crust have placed
them. The sandstones, the calcareous rocks, the marls, the gravels,
even the clays deposited by water under an enormous pressure, are
stratified—that is to say, deposited in layers, like the courses of
a building, and present an excellent foundation. The hill there on
the right, in whose direction your sister’s wood extends, presents,
as you see from this point, escarpments laid bare by the waters of
the brook we are going to cross; observe that the stone, which seems
denuded, presents itself in almost horizontal layers. It is an oolitic
limestone, excellent for building, and on which you may confidently
rely as a foundation also. In these strata, therefore, we may excavate
cellars, and make use of what we have taken from the excavations to
raise the walls. Here we are walking on sandy clays, intermingled with
millstone grit. This also forms a good and incompressible foundation.
It is otherwise with pure clays; not that they are compressible, but,
if they are not secured—if, for instance, they lie on a declivity—they
are liable to slip in consequence of the infiltration of water between
their layers, and the house built on them goes down with them. And
thus you may sometimes see whole villages built on clayey declivities,
descending into the valley. Great attention, therefore, must be paid
to the method in which you build in clays, if you would avoid these
dangers. Sometimes also, when they are greatly compressed by a heavy
building, the clays sink down under the weight, and rise proportionally
at a little distance, in see-saw fashion. Marine sands, pure, fine or
gravelly, are well adapted to receive foundations, because the sand
settles naturally, however slightly moistened it may be. To such a
degree is this the case, that we can form an artificial foundation if
needful by depositing good beds of sea-sand on a questionable soil,
and moistening these beds thoroughly. The finer the sand is and the
freer from clay the better, for its small, hard, equal grains leave
only very slight intervals between them and touch on several points. If
the weight compresses the layer of sand, and forces it to settle down,
the settling down is regular, and consequently harmless. The building
settles thus to the extent of some fractions of an inch, according to
its weight; but it does not dislocate, because it settles uniformly.
The alluvial deposits formed by slowly-flowing waters, such as rivers
or lakes, also compose good foundations, because the layers of gravel
or mud have been gradually deposited, and are closely heaped together
by the liquid that transported them. It is quite otherwise with marshy
soils, for the water, having no current, has allowed vegetables to grow
in its bed. These vegetables on dying are annually replaced by others.
Successive layers of detritus are then formed under very trifling
pressure, leaving between them innumerable cavities, just like a heap
of rotten hay. These deposits are called peat-bogs. Nothing can be
safely placed on these deposits, for they sink down under the lightest
burden. Stop! here we are near the stream, at a point which exhibits
this phenomenon. Stamp on this closely-turfed soil. You perceive that
the ground sounds hollow, and shakes beneath the shock. Sometimes these
peat-beds reach to such a depth, through the accumulation of vegetable
detritus, that the bottom can scarcely be reached. If you build upon
these, your construction will gradually sink, often unequally, on
account of the inclination of the sub-soil, so that the building will
lean to one side. It is thus that at Pisa and at Bologna, in Italy,
there are towers which inclined thus while they were being built, until
the turf was completely compressed under their weight. When these soils
occur, the turf must be removed, the rock or gravel must be reached,
or piles must be driven in very close to each other, until they can be
forced no deeper. Then, on the heads of these piles is placed what is
called a raft, a kind of wooden framing, between the spaces of which
concrete is poured, and on which the first courses of masonry are
placed. Whole cities are built thus. Venice and Amsterdam rest only
upon forests of piles driven in mud, which is spongy, because it was
formed under a shallow sheet of water which had not power to compress
it.
[Illustration: FIG. 6.]
“But it is not enough to know the nature of the soil on which a
building is to be erected; we must also examine the subjacent
water-courses, and how the rain-water flows off on the surface of the
ground, or beneath it. The presence of a bed of clay, however thin,
between strata of limestone, grit or sand, is a most important fact to
the builder; for such beds being impervious—that is, not allowing the
rain-water to penetrate them—give rise to currents or sheets of water,
which may occasion most disastrous consequences to the foundations.
Examine this greenish layer just here, along the escarpment;—it is of
clay; it is very thin, and cannot retain water; but suppose it were
20 inches thick. The rains, which will easily penetrate the gravel
placed above, will be arrested by this layer of clay, and pursue their
course along its plane of inclination, and they will gradually form
cavities like small grottoes, and a concealed current. If you build
a cellar wall or a foundation descending below that accumulation of
water, it will reach your wall and penetrate it, in spite of your
efforts, and will fill your cellars. It will consequently be necessary
at the outset to divert this accumulation of water by collecting it in
a drain to keep it away from your buildings. Give me your note-book,
that I may show clearly what I mean by a sketch—(Fig. 6). Let A B be
the stratum of clay, C D the pervious stratum of gravel or sand. A
sheet of water running from E to F will be formed after every shower.
This sheet will be arrested by the foundation or cellar wall G H, and
will soon permeate it, since it cannot reascend nor penetrate the
clay. We must, therefore, provide, at I, a transverse drain, with
openings on the upper side, through which water will find its way into
the channel shown in sketch K. This drain will take the water thus
collected wherever you like, and leave the wall G H perfectly dry. You
understand, don’t you?
“But if you have to lay your foundations entirely in clay, you must
adopt much more serious precautions: for, as I told you just now, the
whole bed of clay may chance to slip.
[Illustration: FIG. 7.]
“Banks of clay are apt to slip, especially when they present such a
section as I have drawn—(Fig 7). Let A be a bed of rock, B a bed of
clay. Rain-water falling on the upper side from D to C, will pass at
C below the bed of clay; and if the rain is persistent, it will form
from C to E a soft, slippery, soapy stratum, so that the clay bed C B E
will slide over it by its own weight, but especially if at G you have
burdened it with a building.
“How, then, can we guard against the danger? First, by collecting the
water at C into a sewer, or a dry stone drain, so that it may not pass
under the clay bed,—in case the latter is very thick. Secondly, if it
is only a few yards thick, by getting down to the rock or gravel for
the foundation wall, and placing a collecting sewer at I, as above.
Then the triangular bed of clay, C I K, will not be able to slide,
being kept up by the firmly-planted and loaded wall. The part of the
clay lying below, not being moistened from above, will not slip. But
this wall, H, and its drain, I, must be thick enough to resist the
pressure of the triangle C I K.
“You perceive, then, how important it is to understand the soils on
which you have to build; and how essential it is for an architect
to have some acquaintance with geology. Remember this well, for the
architects of the preceding generation have shown a contempt for these
studies, and have relied on their contractors in many instances where
that knowledge was required.
“We shall also take into consideration muddy low-lying soils, permeated
by water, which cannot be dug into, because their consistency is
little better than that of compact mud, and in which the deeper you
dig the less resistance you meet. When these soils are not of a turfy
description, contain little vegetable detritus, and always retain the
same quantity of water, you can build upon them, for water is not
compressible. Your building is then a kind of boat; the only question
is, how to prevent the water from escaping, from receding under the
weight of the structure as it does under that of a boat. When you
plunge into a bath half full of water, the liquid rises along the brim
proportionately to the volume of your body. But suppose that a board
cut out so as exactly to fit the outline of your body, prevents the
water from rising around you, you will not be able to sink into the
water, and it will bear you on its surface. Well, then, the problem of
building in a muddy soil consists in preventing the mud from rising
around the house in proportion to the pressure. I must once more give
you a sketch, showing the method of securing a successful result in
this particular case. (Fig. 8.)
[Illustration: FIG. 8.]
“Let us suppose we have been digging in ‘made ground’ A, _i.e._, ground
in which we cannot build with security. At B we reach the virgin soil,
but it is very moist—mud of old formation, permeated by water, and in
which one sinks in walking. The deeper we go into it the softer we find
it. A bar thrust down to the depth of two or three yards discovers no
bottom, and the holes made in it are immediately filled with water.
Piles driven in sink up to the head. Now, there can be no doubt that
for an ordinary building it will not do to spend in foundations double
what the building itself would cost. We must consider, therefore. In
this case we shall dig a trench of about 1 foot 6 inches to 2 feet
deep, to receive the walls forming the perimeter of the house, as
drawn at E; then, in these trenches, and over the whole area of the
building, we shall pour concrete, having a thickness of 2 feet to 2
feet 6 inches, between the trenches, as at F. We shall thus have formed
a cover of homogeneous material, which will prevent the mud, G H,
comprised within its edges, from rising. The weight of the made ground
A will suffice to keep down the rest. On a plateau of this kind you
will be able to build securely.
“You will, perhaps, ask me what ‘concrete’ is, and how it is made. You
will learn this later on.”
Talking and making sketches, Paul and his cousin had reached the slope
of the hill on which the house was to be built.
“The situation is good,” said Eugène. “We have an excellent calcareous
soil, from which we shall even be able to get stone or rubble fit for
building. Here, on the lower slopes, we have fairly clean sandy clay,
with which we shall make brick. And there is the spring of fresh water
coming from the wood, and passing out below the lowest of the limestone
beds; we shall easily secure it, and lead it along the house, where it
will be doubly useful, for it will give us water for the requirements
of the household, and carry off in a drain all the house sewage and
impurities, which we will discharge into that old excavation which I
see on our left.
“However, we must examine before we proceed, for it seems to me that
these beds have already been worked at some points. We should be very
likely to meet with some of those carelessly-conducted quarryings which
are too common in this neighbourhood.”
“How,” asked Paul, “can good building-stone be distinguished from that
of inferior quality?”
“It is not always easy to distinguish it, and in this, as in many other
branches of knowledge, experience must confirm theory. Among calcareous
stones, which comprise, with certain sandstones, the materials that
can be easily quarried and worked, some are hard, others soft; but the
hardest are not always those which best resist the effects of time.
Many limestones contain clay, and as this retains water, when frosts
supervene, these clayey parts swell, and burst blocks whose substance
is composed of carbonate of lime, and also of silica, in larger or
smaller quantity. Limestones free from clay are those which best resist
moisture, and are least liable to be damaged by frost. When, as here,
we have beds laid bare by erosion, it is easy to distinguish the good
from the defective ones. Thus, observe that large dark-looking mass,
whose smooth bare edge has been covered with lichens for centuries;
it is of an excellent quality, for lichens spread over a rock very
slowly; and to enable them to attach themselves to this stone and give
it that grey speckled appearance, the limestone must have resisted the
decomposing action of the atmosphere. Now, look at that bed of nearly
pure white, and which seems so sound. Well; it has this fair appearance
only because at every frost it has lost its skin; its surface has
been decomposed. Touch this rock, and you will observe a white dust
remaining on your hands. It is so, is it not? The quality of this
block is consequently bad; in fact, you see that below it the grass is
covered with small calcareous exfoliations, whereas the turf under the
grey block is quite free from dust. It is then very desirable for an
architect, when he intends to build, to go and see the quarries, and
observe how the beds that compose them stand when exposed to the air, a
thing—I may tell you—our brethren rarely do.”
LESSON THE SECOND.
Paul was greatly pleased with the method adopted by his cousin for
giving him the first notions of building. In the evening he presented
as his day’s work a fair transcription of all that his teacher had
explained to him on the ground. He even illustrated his text by some
pretty good diagrams. The corrections were quickly made after dinner.
But next day the incessant rain prevented them from going out, and
Eugène decided that the second lecture should be given in the house.
“We shall have illustrations enough before us; the _château_ itself
will supply them. We will go through it from cellar to attic, and study
its materials and methods of construction—to criticize them if they
are bad, or to take note of them if they are good.” When teacher and
pupil had gone down into the cellars, Eugène began by saying, “Look
how damp this cellar wall on the side of the courtyard is; and see
how the mortar in the joints of the stones has fallen, owing to two
causes:—first, in building these walls, the precaution was not taken of
cementing them on the outside, so as to make the water in the ground
run down to the bottom; second, the mortar employed in the building
was not made with hydraulic lime. There are two principal kinds of
lime: fat or rich lime and hydraulic lime. The first is obtained by
burning the compact limestones usually found at the top of the beds;
it is called fat because when slaked it is glutinous and sticks to the
tool with which it is mixed; this lime, on being immersed in water,
swells and sends forth a dense vapour, as you may have observed, and
mixed with sand is slow in setting. Employed above ground, mortars made
with this lime become at length very hard, but retain more or less
for a time a certain plasticity. These mortars, however, as they are
slow in setting, are readily softened by water, and cannot then ever
harden. Hydraulic limes, on the other hand (obtained by burning the
lias limestones), when mixed with sand, soon become very hard, and set
all the better for being in a damp place. Hence this lime is called
_hydraulic_, because it is employed for all masonry-work under water.
In default of lias limestones, artificial hydraulic limes are made, by
grinding a certain proportion of clay with a limestone suitable for
making ordinary lime. Hydraulic lime is tested by slacking—that is to
say, mixing it with water; when it slakes with the production of very
little vapour.
“It is with hydraulic lime that concretes, of which I spoke to you
yesterday, are made. The mortar being prepared, a certain proportion
of hard gravel, about the size of eggs, is mingled with it; the whole
is well mixed and thrown into the excavations, where it is rammed with
wooden rammers. If the lime is good and the concrete well made, it
forms a veritable rock, similar to the conglomerates or pudding-stone
of natural formation. As, when set, water penetrates with difficulty
through these concretes, they prevent that percolation of subjacent
water to which cellars made in wet grounds are liable.
“If the wall you see there had been built with mortar made with
hydraulic lime, it would have been sound, and the mortar joints would
have been as hard as the stone itself. You will easily understand that
when the water has gradually softened and liquefied the mortar in
the beds and joints at the base of a wall, the stones which compose
it settle, and all the rest of the building suffers. That is why the
front of the house, towards the court, presents a considerable number
of cracks, that are filled in from time to time, but of course with no
result in doing away with the cause of the mischief.
[Illustration: FIG. 9]
[Illustration: FIG. 10.]
“You observe that the cellar wall which receives the arch of the vault
is very thick, much thicker than is the wall of the ground floor. The
latter is scarcely 2 feet thick, whereas this is full 3 feet. This
additional thickness is given to the inside principally to receive the
springing of the vault. A sketch will enable you to understand the
reason of this arrangement. Let A (Fig. 9) be the thickness of the
wall of a house on the ground floor—a thickness of 1 foot 8 inches if
cellars are wanted beneath the ground floor; the floor line being at
B and the outside ground line at C, it will be well first to indicate
the floor line by a projection,—a greater thickness given to this wall
on the outside, say of 2 inches. At A, then, the wall will have a
thickness of 1 foot 10 inches. Your cellar arch being drawn at D, we
must reserve a resting-place of at least 8 inches, to receive the first
arch-stones of the spring of the vault; then it is well to give on
the side next the ground a greater projection, to make a good footing
for the plinth; this projection being 2 inches, we shall have at F a
thickness of 2 feet and at G 2 feet 8 inches at least, as it will not
do for the wall which rises to bear on the oblique beds of the vault,
otherwise it would not have a solid footing, and would be weakened or
reduced in thickness by this arch, which would penetrate it, as we see
in the drawing I. But come here into this other cellar, which belongs
to the oldest part of the _château_, and is built with good stones.
The builder did not wish to lose space within, and as he built with
worked stone he sought to economise material. What, then, did he do?
(Fig. 10.) He gave his cellar wall only the thickness of that of the
ground floor; at regular distances he put massive corbels 2 feet above
the floor; upon these corbels he carried arches projecting 10 inches,
and on these arches, which replace the extra thickness or counter-wall
of which I spoke to you just now, he carried his vaulting arch. This
perspective sketch will enable us readily to understand this method of
construction. The upper wall thus leaves the vault perfectly free and
rises plumb over its lower face.
“Is it all clear to you? Well, let us go and look at that little
flight of steps which perhaps you have never attentively examined. It
is 4 feet 3 inches wide, which was large enough to afford a passage
to the _queues_ of wine. Observe (Fig. 11): the ramping vault is
composed of as many arches, one above another, as there are steps;
that is extremely well managed, solid and easily built. In fact, when
the stone steps are laid, over above them is successively fixed the
same wood centre which, of course, is raised at each step; and upon
this centre an arch is built, which is quickly done, as the stones
are worked ready. In this way the arches follow the section of the
steps, and the centre being shifted—after each arch is keyed—to the
next step commencing from the bottom, two men can turn five or six
of these arches in one day, so that if there are twelve steps, this
ramping vault may be built in two days. Look, I will show you how this
construction should be denoted in perspective and geometrical section
in your _résumé_ to-day—A and B.
[Illustration: FIG. 11.]
“Let us go up to the ground floor. Look at the efflorescence resembling
cotton wool on the interior of the walls: it is the saltpetre which
forms inside the stone, and, through the humidity of the ground,
crystallizes on the surface. This saltpetre affects the stone
injuriously, ultimately eats it away, and throws off any painting that
we might endeavour to use as a counteractive on the interior surface.
Mastic cements are made to stop the effects of the saltpetre, but
these means only delay its appearance for a short time without curing
the evil, and this cement soon falls off in a crust. It is therefore
necessary in building, especially in the country, to prevent the damp
of the ground from rising up in the walls, and to stop it at the ground
level. The interposition of a layer of pitch beneath the plinth has
sometimes been tried, in order to prevent the absorption of damp by
the stones—or what is called capillary attraction—but this method is
very inefficient. The pitch oozes out under the pressure, as it does
not harden sufficiently to bear that pressure, or it decomposes and
combines with the lime. The best plan is to lay a course of slates in
the mortar-bed between the first lower courses of the plinth. The slate
effectually hinders that effect of capillary attraction, and the damp
is unable to rise in the walls.
[Illustration: FIG. 12.]
“Now observe this front wall in the court: it forms a protuberance
at the floor level of the first story. We call that a bulging of the
wall. Instead of preserving its vertical plane, as it should have
done, it has bulged out; and why? Because it has been thrust out by a
force acting from within outwards. What is that force? It might be an
arch; but there is no arching on the ground floor. It can therefore be
only the floor. It is not clear at first sight how a floor, which is a
horizontal plane, can thrust; for to thrust, we must suppose the floor
to expand in one direction, which cannot be. But see what happens. Give
me your best attention.... Formerly, to compose a floor, large beams
were laid from wall to wall, and upon these beams lighter pieces of
timber, called joists; then on these was laid a bed of earth, gravel,
or sand, and upon that a surface of mortar to receive the tiling. This
made a very heavy mass. Now, as a piece of timber, even of considerable
section, bends in time under its own weight—that is to say, from being
straight becomes curved—its tendency to bend will be proportionally
greater when it is weighted. The more it bends, the more powerful its
thrust upon the inner surface of the walls in which it has its bearing.
It is this pressure upon the interior surface that tends to thrust the
wall outwards. But if, as in this case, in order to relieve the bearing
of the beams, struts of wood have been put underneath (Fig. 12), this
effect of thrust is all the more sensible because the arm of the lever
is longer. You do not quite understand, I see. A sketch will make it
clear to you. Let A be the section of the wall, or, if you will, its
thickness. If the beam bends according to the line C D, there occurs
a pressure at D, which produces a thrust at F and the rounding of the
wall, as indicated by the dotted curves. Supposing even that in lieu
of the strut E we have a stone corbel, the effect produced will be
the same, though less forcible, unless the tail of the corbel reaches
through the wall, as you see marked at I, and this tail K is weighted
in such a manner that the weight neutralizes the pressure which the
beam exerts at the end L. This has not been done here, where instead
of the wood strut, a corbel was put. This corbel has but a middling
hold in the wall, and the latter, formed of small stones not very well
built, has not sufficient cohesion to resist the thrust exerted by the
deflection of the beams. But why, you will ask me, has this effect been
produced at the floor level of the first story and not above? Because,
by the effect of the bulging we find here, the wall has inclined above
towards the inside, and has thereby squeezed the second floor—its
surfaces being placed, by their very inclination, perpendicularly
to the curve line of the upper beams, as I indicate to you at M,
exaggerating the effect for the purpose of making it clearer.
“You see that each detail merits attention, and that the builder ought
to have a good reason for everything he does.
“In work of every kind we learn to avoid faults only by analysing and
searching into their causes and ascertaining their effects. To become
a good builder, therefore, it is not enough to familiarize one’s self
with rules of construction, which cannot provide for all contingencies;
we must see and observe much, and ascertain defective points in
buildings that have been tested by time; just as physicians become able
to determine what a good constitution is only by studying diseases and
their causes. For the most part we appreciate what is good only through
observing what is bad; if, in the absence of the bad, we are able to
admit that there is such a thing as the good. An old proficient in
architecture, who, when I was about your age, was so kind as to aid
me with his advice, used often to say to me: ‘I can tell you, my dear
fellow, what you must avoid in the art of building;—as to explaining to
you in what the good and the beautiful consist, you must find out that
yourself. If you are a born architect, you will know well enough how
to discover it; if not, all that I could show you, all the examples I
could place before you, would not give you talent.’ And he was right.
The sight of the finest works in architecture may pervert the minds of
students, if it’s not been explained to them how the authors of these
works succeeded in making them beautiful by having avoided such or such
faults.
“But you have enough to write out for to-day. Make a fair copy of these
sketches opposite your text, and we will examine it this evening.”