CHAP. II
Of the Solidity of Buildings
ARTICLE I
Of the Choice of Materials
THE Materials of which
Vitruvius
speaks are, Stone, Brick, Wood, Lime, and Sand.
All the Stones are not of one sort, for some are soft, some harder, and some extreamly hard.
Those that are not hard are easily cut, and are good for the Inner Parts of the Buildings, where they are cover'd from Rain and Frost which brings them to Powder, and if they be made use of in Buildings near the Sea, the Salt Particles of the Air and Heat destroys them.
Those that are indifferently hard, are fit to bear Weight; but there are some sorts of them, that easily crack with the heat of the Fire.
There is likewise another sort of Stone, which is a kind of Free-Stone; some are Red, some Black, and some White, which are as easily cut with a Saw as Wood.
The best Bricks are those which are only dry'd and not baked in the Fire; but there are many Years required to dry them well: and for this Reason, at
Utica
, a City of
Africa
, they made a Law, That none should make use of Bricks which had not been made five Years: For these sort of Bricks, so dry'd, had their Pores so close in their Superficies, that they would swim upon Water like a Pumice-Stone; and they had a particular Lightness, which made them very fit for all sorts of Buildings.
The Earth of which these Bricks were usually made was very Fat, and a sort of White Chalky Clay without Gravel or Sand, which made them Lighter and more Durable; they mixed Straw with them to make them better bound and firmer.
The Woods which were made use of in all Buildings, are Oak, Poplar, Beech, Elm, Cypress, Firr; but some of them are not so proper for Building as others.
The Firr, because it has great plenty of Air, and Fire, and but little Earth and Water, is light, and does not easily bend; but is very subject to Worms and Fire.
The Oak which is more Earthy lasts for ever under Ground; but above Ground is apt to cleave.
The Beech which has little of Earthiness, Humidity and Fire, but great plenty of Air, is not very solid and easily breaks.
The Poplar and the Linden Trees are only good for light Work, they are easily cut and so finest for Carving.
The Alder is good to make Piles of in Marshy Places.
The Elm and the Ash have this property, that they do not easily cleave, and that they are pliable.
The Yoke-Elm is likewise pliable, and yet very strong; this is the Reason that they made Yokes for their Oxen of them in Old Time.
The Pine and the Cypress have this defect, that they easily bend under any Weight, because of their great Humidity; but they have this Advantage, that their Humidity does not engender Worms, because of their Bitterness which kills them.
The Juniper and the Cedar have the same Vertue of hindering Corruption: the Juniper by its Gum, which is call'd
Sandarax
, and the Cedar by its Oil call'd
Cedrium
.
The Larch-Tree has likewise the same Vertue, but its particular property is, that it will not burn. There is a remarkable Story of this Wood, which is, That when
Julius Cæsar
besieg'd a Castle at the Foot of the
Alpes
, there was a Tower built of this Wood, which prov'd the Principal Defence of the Place. He thought to take it easily by making a great Fire at the Foot of the Tower, but for all this great Fire, the Tower did not suffer the least Damage.
The Olive-Tree is likewise very serviceable, if it be put in the Foundations, and Walls of Cities; for after it has been singed a little, and interlaced among the Stones, it lasts for ever, and is out of all danger of Corruption.
Lime is made of White Stones or Flinty Pebbles, the harder the Stones are which 'tis made of, the better it is for Building. That which is made of soft Spongy Stones, is proper for Plastring.
There are five sorts of Sand;
viz.
Sand that is dug out of the Ground, River Sand, Gravel, Sea-Sand, and Pozzolana, which is a Sand peculiar to some Parts of
Italy
.
The best Sand is that which being rubb'd between the Hands makes a little Noise, which that Sand does not, which is Earthy, because it is not rough. Another Mark of good Sand is, that when 'tis put upon any Thing that is White and shak'd off, it leaves no Mark behind.
The Sand which is dug out of the Earth has all these Qualities, and is esteem'd the best.
Vitruvius
makes four sorts of it;
viz.
White, Black, Red, and Bright like a Carbuncle.
If it happen that there be no good Place to dig Sand in, we may make use of Sea-Sand, or River-Sand, which is likewise better for Plastering than the Sand which is digged, which is excellent for Building, because it drys quickly. Gravel likewise is very good, provided the grosser Parts be taken away. Sea-Sand is worst of all, because 'tis long adrying; and for this Reason, where 'tis made use of in Building, they are forc'd to desist sometimes till it dry.
The Sand which is found near
Naples
call'd
Pozzolana
is so proper to make good Mortar, if it be mixed with Lime, that not only in the ordinary Fabricks, but even in the very bottom of the Sea it grows into a wonderful hard Body. In Old Times they made use of it for Moles or Ports of the Sea, for after having made with Piles and Boards a Partition, they fill'd up the whole Compass of the Partition with this Mortar, which dry'd of it self in the middle of the Water and became a solid Body.
ART. II
Of the Use of the Materials
THE first thing we should have a Care of before we begin to build, is, to have the Stones dug out of the Quarry before they be used, and to expose them in some open Place, to the end that those which are endamaged by the Air, during this Time, may be put in the Foundation, and those that prove Durable and Good may be kept for the Walls above Ground.
We must likewise have a great care of the Wood which we make use of; That it be cut in a seasonable Time, which is in Autumn and Winter; for then it is not full of that superfluous Humidity which weakened it in dilating its Fibers, but it is firm and well closed by the Cold. This is so true, that the Wood of Trees which grow and become very great in a little Time, by reason of their great Humidity, is tender and apt to break, and very unfit for Building Which Experience shows us particularly in those Firrs call'd
Supernates
, which grow in
Italy
, on that side the
Apennine
, towards the
Adriatick
-Sea, for they are great and beautiful, but their Wood is not good for Building; whereas those on the other side of the Mountain, which are exposed to Heat and Dryness, call'd
Infernates
, are very good for Building.
This superfluous Humidity endamages Trees so much, that we are sometimes constrain'd to make a hole at the foot of the Tree and let it run out, which is the occasion of the Practice which is observ'd in cutting of Wood for Building, to Tap that Tree at the Foot, cutting not only the Bark, but even some part of the Wood it self, and so leave it for some time before it be Fell'd.
It is likewise easie to judge of what great Importance the draining of this superfluous Humidity is for strengthning
Lib. 1.
Chap. 5.
the Timber, and hindring Corruption, from this, That those Piles which are interlaced among the Stones in the Walls and Fortifications of Towns endure for ever without Corrupting, when they have been burnt a little on the outside.
Lib. 1.
Chap. 11.
Lib. 2.
Chap. 8.
Bricks ought not to be made use of but in very thick Walls; for this reason they did not build with Brick in
Rome
, for to save Ground; they were not permitted to make the Walls of their Houses above a Foot and a Half thick, which Makes about 16 Inches and a half of our Foot.
They likewise never made the top of their Walls with Brick; for the Brick of the Ancients not being baked, this part of the Wall would have been easily endamaged; for this reason they built it with Tiles, a foot and a half high, comprizing the Cornish or Entablature which was made likewise of Tiles to cast off the Water and defend the rest of the Wall. They likewise chose for these Cornishes the best Tiles,
viz.
those that had been long on the top of the Houses, and given sufficient Proof that they were well baked and made of good Matter.
The Walling with Brick was so much esteem'd among the Ancients, that all their Fabricks, as well publick as private, and their most beautiful Palaces were built with them. But that which principally made this sort of Building be esteem'd, was its great Duration; for when expert Architects were called to make an Estimate of Buildings, they always deducted an 80th. part of what they judged the Building cost for every Year that the Wall had been standing, for they supposed that the Walls could not ordinarily endure more than Fourscore Years; but when they valued Buildings of Brick, they always valued them at what they cost at first, supposing them to be of an Eternal Duration.
To make the right use of Lime and Sand, and to make good Mortar of them, it is necessary that the Lime be first well Quench'd, and that it be kept a long time, to the end that if there be any Piece of it that is not well burnt in the Kiln, it may, being extinguished at leasure, soften as well as the rest. This is of Great Importance particularly in Plastering and Works of
Stuck
, which is a Composition of Marble finely beaten with Lime. For if any little Pieces remain that are not well baked, when they come to be made use of, they crack and break the Work.
The way to know whether the Lime be well Quench'd, is thus: You
Lib. 7.
Chap. 3.
may thrust a Chip of Wood into it or a Knife, and if the Chip of Wood meet with any Stones, or that the Knife comes out clean without any sticking to it, it signifies the Lime was not will burnt; for when 'tis well Quench'd, it is Fat and will stick to the Knife; but the quite contrary happens to Mortar, for it is neither well prepar'd, nor well mix'd, if it stick to the Trowel.
For to make the right use of
Lib. 2.
Chap. 4.
Sand, you must first consider what it is to be employ'd in; for if it be Mortar for Plastring, you must not make use of Sand that was lately dug out, for it drys the Mortar too fast, which cracks the Plastring; but quite contrary if it be to be employ'd in Masonry, it must not have been a long time expos'd to the Air, for the Sun and the Moon do so alter it, that the Rain dissolves it, and turns it almost all into Earth.
Lib. 2.
Chap. 5.
The Proportion that Sand and Lime ought to have to make good Mortar, should be three parts of Sand that is dug, or two parts of River-Sand or Sea-Sand against one of Lime, and 'twill be yet much better, if you add to the Sand of the Sea and the River a third part of Tiles well beaten.
Lib. 7.
Chap. 3.
One of the Principal Things that is to be observ'd in making Mortar, is, to mix it well. The Grecian Workmen were so careful of this, that they Tewed it a great while, putting Ten Men to every Vessel wherein they wrought it, which gave so great a hardness to the Mortar, that when any big pieces of Plaster fell off the Old Walls, they made Tables of it.
ART. III
Of the Foundation
Lib. 6.
Chap. 11.
THE Foundation is the most important part of the Fabrick; for the Faults committed in it cannot be so easily remedied as in other parts.
To lay the Foundation well, you
Lib. 1.
Chap. 5.
must dig till you come to solid Ground, and even into the solid as much as is necessary to support the Weight of the Walls; it must be larger below than above the Superficies of the Earth.
Lib. 3.
Chap. 3.
When you have found firm Earth to make it more solid, you must beat it with a Rammer; but if you cannot arrive at solid Earth, but find it still soft and spungy, you must dig as far as you can, and drive in Piles of Alder, Olive, or Oak, a little singed, near together, and fill up the void Places between the Piles with Coal.
Lib. 1.
Chap. 5.
In short, you must make all Masonry with the most solid Stone that can be found for this use.
To make the Binding of the Stones the stronger in the Foundation of great Fabricks, you must put Piles of Olive a little singed and placed very thick from one Parement or Course to another, which serves, as it were, for Keys and Braces; for this Wood so prepar'd, is not subject to Worms, and will endure for ever, either in the Earth or in the Water, without the least Damage.
Lib. 6.
Chap. 11.
When you would make Cellars, the Foundations must be much larger; for the Wall that is to support the Earth requires a greater thickness to resist the strong Efforts that the Earth makes against it in Winter, at which time it swells and becomes more heavy by reason of the Water it has drunk up.
ART. IV
Of the Walls
Lib. 4.
Chap. 2.
THE right ordering of Stones joined with Mortar, which is call'd Masonry, is sevenfold; there are three of them which are of hewed Stone;
viz.
that which is in Form of a
Net
, that which is in
Binding
, that which is call'd the
Greek Masonry
. There are likewise three sorts of Masonry of unhewed Stones;
viz.
that which is of an
equal Course
; and that which is of an unequal, and that which is fill'd up in the middle; the seventh is compounded of all the rest.
The
Net-Masonry
is that which is made of Stones perfectly squar'd in their Courses, and are laid so, that the Joints go obliquely, and the Diagonals are the one Perpendicular, and the other Level. This is the most pleasing Masonry to the Sight, but it is apt to crack. See the Figure A. Table I.
The Masonry call'd the
Bound-Masonry
, is that, as
Vitruvius
explains it, in which the Stones are plac'd one upon another like Tiles; that is to say, where the Joints of the Beds are Level, and the Mounters are Perpendicular; so that the Joint that mounts and separates two Stones falls directly upon the middle of the Stone which is below.
Some Authors call this sort of Masonry
Incertain
, but they are mistaken; for they read
Incerta
instead of
Inserta
; it is not so Beautiful as the Net-work, but it is more solid and durable. See the Figure BB. Table I.
The Masonry which
Vitruvius
says is particular to the
Greeks
, is that, where after we have laid two Stones, each of which make a Parement or
Course
, another is laid at the end, which makes two Parements or
Courses
, and all the Building through observe this Order. This may be call'd
Double-Binding
; for the Binding is not only of Stones of the same
Course
one with another, but likewise of one
Course
with another
Course
. See Figure CC. Table I.
The manner of Walling by unequal Courses call'd
Isodomum
by the Ancients, differs in nothing from the Masonry call'd
Bound-Masonry
, but only in this, that the Stones are not hewed. See Figure D. Table I.
The other manner by unequal Courses call'd
Pseudisodomum
is also made of unhewed Stone, and laid in
Bound-Work
, but they are not of the same thickness, and there is no equality observ'd, but only in the several Courses, the Courses themselves being unequal one to another. See Figure A. Table I.
The Masonry which is fill'd up in the middle, call'd by the Ancients
Emplecton
, is likewise made of unhewed Stone and by Courses, but the Stones are only set in order as to the
Parements
or
Courses
, but the middle is fill'd up with Stones thrown in carelesly among the Mortar. See Fig. FF, GG, H. Table I.
Among all these sorts of Masonry, that will always be best which is made of Stones of an indifferent size, rather lesser than greater; to the end that the Mortar penetrating them in more parts may bind them faster, and the strength of the Mortar does not so soon decay. For we see that the Mortar which is laid in the Joints or Seams of the greater Stones with time decays and turns to Dust, which never happens to the most Ancient Fabricks which have been built of little Stones. From thence we may conclude, that it is ill Husbandry to be sparing of Mortar.
For this reason
Vitruvius
proposes another sort of Masonry, which may be call'd the
Compound Masonry
, for it is all the former together, of Stones hewed and unhewed, and fastned together with Cramp-Irons. The Structure is as follows: The
Courses
being made of hew'd Stone, the middle place which was left void is fill'd up with Mortar and Pebbles thrown in together; after this they bind the Stones of one
Parement
or
Course
to those of another with Cramp-Irons fasten'd with melted Lead. This is done to the end, that the abundance of Mortar which is in the middle may furnish and communicate a sufficient Humidity to the Joints of the great Stones which make the
Parements
. See the Figure K. Table I.
There are many Precautions to be given to make the Masonry more firm and durable, and these Precautions are common to all the different sorts of Masonry.
Lib. 1.
Chap. 5.
When you would have the Walls very thick, for great and heavy Buildings, you must strengthen the inner part of the Wall with long Piles of singed Olive, which serves for Keys and Braces, for this Wood being so prepar'd never corrupts.
Lib. 6.
Chap. 11.
Vide Index.
It is likewise of great Importance for the strength of Walls, that all be directly Perpendicular, and that the
Chains
, the
Pillars
and
Pieds-droits
or
Piers
be so situated, that
solid
always answer'd to the
solid
; for if there be any part of the Wall or any Pillar that carrys false, it is impossible the Work should continue long.
There are also two ways of strengthning the Walls, which are either to ease them of their own weight, or of that of the Earth which they are to support.
The first way of easing is in those Places where there are void spaces, as above Doors or Windows. These easements may be made two different ways; the first is to put over the Lintel which supports the Wall, which is over the void space of the Gates and Windows, two Beams, which lying or resting below directly upon
Pieds-droits
or
Piers
meet together above.
The other way is, to make directly over the void spaces Vaulted Arches with Stones cut corner-ways and tending to one Center. For the Walls be so strengthned by the means of these easements, that part of the Wall which is below will not sink at all being easied of the load of the part that is above, and if some defect should happen by tract of time, it may be mended without propping that which is above.
The second way of easing, is, for Walls that are made to support the Earth; for, besides the extraordinary thickness which they ought to have, they should have likewise Buttresses on that side next the Earth, so far distant one from another as is the breadth of the Wall; they ought likewise to have an
Emparement
or large Foundation which must be equal to the height of the Wall, so that they go diminishing by degrees from the bottom to the top, where they come to equal the height of the Wall.
Lib. 1.
Chap. 5.
The effect of these
Buttresses
is not only to support the Earth by their Resistance, but likewise to lessen its Efforts when it swells, in dividing it into many parts.
Lib. 6.
Chap. 11.
And it be judg'd that these
Buttresses
be not sufficient, the Wall also which supports the Earth must be strengthned with other
Buttresses
within.
ART. V
Of Flooring and Ceiling
THere are four sorts of Flooring, some are upon the
Superficies
of the Ground, others between two Stories, others make the Roof of the House in Plat-form, and the last is
Plat-Fond
.
To make those Floors that are upon the Ground, you must first make the Earth smooth and plain, if it be firm and solid, if not, it must be beaten with a Rammer with which they ram down their Piles; and after having cover'd the Earth with the first
Lay
or
Bed
, call'd
Statumen
by the Ancients, which was of Flinty Stones about the bigness of ones Fist, among which was mixed Mortar made of Lime and Sand. Then they laid the second
Bed
, which they call'd
Rudus
, which was made of lesser Stones, of which there were three Parts for one of Stone if they were new, for if they were taken out of old Buildings, five parts of Stones or Pibbles would be required for two of Lime.
The
Greeks
had a way of making their
Lib. 7.
Cap. 4.
Floors in those low places where cold and humidity ordinarily reign, which freed them from these Inconveniences. They digged the Earth two Foot deep, and after having beaten it well, they laid a Bed of Mortar or Cement a little sloping from either side to the Channel, which convey'd the Water under Ground; they laid a Bed of Coal upon the first Mortar, and having beaten them well, they cover'd them with another Cement or Mortar made of Lime, Sand and Ashes, which they made smooth when it was dry with a Polishing-Stone. These Floors presently drank up the Water that fell upon them, that one might walk barefoot without being incommoded by the Cold.
For the Floors which are between two Stories, there must be a particular care taken, that if there be any Partition below it, that it may not touch the Flooring for fear lest if the Flooring came to sink a little, it might be broke upon the Partition which remains firm.
To make these Floorings, the Boards must be nailed at each end upon every Joist, to the end they may not warp; these Boards or Planks being cover'd with Straw, to hinder the Lime from wasting the Timber, the first Bed must be laid, made of a mixture of Mortar and little Stones a hand breadth, which must be beaten a long time with Iron-Levers, and so it must make a solid Crust which must be nine Inches thick; upon it shall be laid the
Noyau
or
Ame
, which must be at least six inches thick: It must be made of Cement, with which must be mix'd one part Lime for two parts
Lib. 7.
Cap. 4.
of Cement. Upon the
Ame
or
Noyau
is placed the
Parement
made with the Rule, afterwards it must be scrap'd and all the Eminences and Inequality taken away: After that must be laid a Composition of Lime, Sand and beaten Marble, to fill equally all the Seams or Joints.
If a Flooring be to be made in the open Air, as upon
Terrasses
, that may endure Rain or Frost without any Damage; you must nail upon the Joists two Ranks of Boards across, one above the other; and having laid the first Bed, as is said before, it must be Paved with great Square Bricks two Foot Square, which must be hollow'd in the Ends in the Form of a half-Channel, the breadth of an Inch, which must be fill'd with Lime mixed with Oil. These Square Bricks must be higher in the middle, sloping two Inches for every six Foot; that is to say, a Forty-eighth Part. Upon these Square Bricks must be laid the
Ame
; upon which, after it has been well beaten, as well as the rest, must be put great Square Stones; and to hinder the Moisture from hurting the Boards, it is good to pour as much of the Lees of Oil as they will soak up.
The under part of the Flooring, and the
Plat-Fonds
, must be made also with great Care. To make the
Plat-Fonds
or
Flat-roofs
, in the Form of a Vault, you must nail to the Joists of the Boards, or to the
Lib. 5.
Chap. 10.
Rafters of the Roof, from two Foot to two Foot pieces of crooked Timber, and Choice must be made of Timber that is not apt to rot; such as,
viz.
Cypress
,
Box
,
Juniper
, and
Olive
; no
Oke
must be made use of, because it will warp and crack the Work. The Joists being fastened to the
Suntmers
, you must fix to them
Spanish-Broom
with
Greek-Reeds
well beaten. These Reeds are in stead of Laths, which at present are made use of to make the Eaves of Houses; over these Reeds must be laid a Plaster of Mortar, made of Sand, to hinder the Drops of Water which may fall from above from endamaging these
Plat-Fonds
. After which, the under part must be Plaster'd pretty thick, making all Places equal with Mortar made of Lime and Sand, that it may be afterwards Polished with Mortar made with Lime and Marble.
The Ancients sometimes made double
Lib. 5.
Chap. 10.
Vaults, when they were afraid that the Humidity which is engender'd, might rot the Wood which is upon by the Vapours which mount up the Vaults. This Method they principally made use of in their Baths.
The
Corniches
which are made use of under the
Plat-Fonds
, ought to be little, lest their great Jetting out, or Projecture should make them heavy, and apt to fall. For this Reason they ought to be made of pure Stuck of Marble, without any Plaster, that all the Work drying at the same time, may be less apt to break.
ART. VI
Of Plastering
TO make Plaster that it may continue a long time, and not crack; you must take Care to lay it on Walls that are very Dry; for if the Walls be Moist, the Plastering being expos'd to the Air, and drying faster than the Walls, will crack.
To do this Methodically, it must be laid, Bed after Bed, or Lay after Lay, having a great Care not to lay one Bed till the other be almost dry. The Ancients put six Lays, three of Mortar made of Lime and Sand, and three of Stuck. The first Lays or Beds were always thicker than the last, and they were very careful to make use of no Mortar made either of Sand or Stuck in their Plastring, that had not been a long time beaten and mix'd together; especially the Stuck, which must be beaten and mix'd till it will not stick to the Trowel.
They took likewise a great deal of Pains to run several times over and beat the Plaster, which gave it a Hardness, a Whiteness, and Polish'd it so well, that it shin'd like a Mirror.
These Plasterings so made, serve to Paint in
Fresco
upon; for the Colours being laid upon the Mortar before it was dry, pierced it, and Embodied with it; so that the Painting could not be defaced though it were wash'd; which would easily be wash'd off if the Mortar were dry.
They likewise laid these Plasterings upon Partitions of Wood filled with fat Earth, nailing Reeds to them, as we do Laths, and daubing it over with Clay, and then putting on another row of Reeds across upon the former, and another Bed of fat Earth or Clay, upon which they laid Beds of Mortar and Stuck, as we have said before.
For the Plastering of low and moist places, they had a great many other
Lib. 7.
Chap. 4.
Precautions, especially within the House; for as what belonged to the Out-part of the House, they contented themselves to Plaster from the Bottom of the Wall to the height of three Feet, with Cement.
But as to the Inward-parts of the House, when the Ground without was higher than the lowermost Flooring; they run up a little narrow Wall against the great one, leaving betwixt the two Walls