Anyone wishes to go through the whole place by the high-level roads, he will be able to use them for this purpose, and so also if anyone wishes to go by the low-level roads.' 

If the usual width of the river is that of one arch construct this bridge with three, and do this in order to allow for the floods. c.a. 46 v. a 

[Ground-plan of castle with la\e and boats on it] [The palace of the prince ought to have a piazza in front] 1 

The rooms which you mean to use for dancing or to make different kinds of jumps or various movements with a crowd of people, should be on the ground floor, for I have seen them collapse and so cause the death of many. And above all see that every wall, however thin it may be, has its foundations on the ground or on well-planted arches. 

Let the mezzanines of the dwellings be divided by walls made of narrow bricks, and without beams because of the risk of fire. 

All the privies should have ventilation openings through the thickness of the walls, and in such a way that air may come in through the roofs. 

Let the mezzanines be vaulted, and these will be so much the stronger as they are fewer in number. 

Let the bands of oak be enclosed in the walls to prevent them from being damaged by fire. 

Let the privies be numerous and be connected one with another, so that the smell may not spread through the rooms, and their doors should all close automatically. [Plans] Kitchens. Pantry. A Words crossed out in MS. 


[Plans] Kitchens. Stable. Eighty braccia wide and a hundred and twenty braccia long in ground plan. Combats by means of the boats, that is the combatants may be upon the boats. Ditch forty braccia. Road below. 

At the angle a should be the keeper of the stable. 

The largest division of the front of this palace is in two parts, that is the width of the court is half the length of the aforesaid front. c.a. 76 v. b 
[With plan] 

Stable for the Magnifico, for the upper part, one hundred and ten braccia long and forty braccia wide. [With plan] 

Stable for the Magnifico, for the lower part, one hundred and ten braccia long, and forty braccia wide, and it is divided into four rows for horses, and each of these rows is divided into thirty-two spaces, called intercolumnar, and each intercolumnar space has a capacity for two horses, between which is interposed a swing-bar. 

This stable therefore has a capacity for a hundred and twenty-eight horses. c.a. 96 v. a 


Give me authority whereby without any expense to you it may come to pass that all the lands obey their rulers, who . . . 

The first renown will be eternal together with the inhabitants of the city built or enlarged by him. 

Let the bottoms of the reservoirs which are behind the gardens be as high as the level of the gardens, and by means of discharge-pipes they will be able to bring water to the gardens every evening every time that it rises, raising the joint half a braccio; and to this let the senior officials be appointed. [With plan] Canal. Weir. Garden. 

And nothing is to be thrown into the canals, and every barge is to be 
obliged to carry away so much mud from the canal, and this is after- 
wards to be thrown on the bank. 

[With plan] Construct in order to dry up the canal and to clean the 
(lesser) canals. 

All people obey and are swayed by their magnates, and these mag- 



Slates ally themselves with and arc constrained by their lords in two 
ways, cither by blood-relationship or by the tie of property; blood- 
relationship when their sons, like hostages, are a surety and a pledge 
against any suspicion of their faith; the tie of property when yon let 
each of them build one or two houses within your city, from which he 
may draw some revenue; and \in addition to this] 1 he will draw from 
ten cities of five thousand houses with thirty thousand habitations, and 
you will disperse so great a concourse of people, who, herding together 
like goats one upon the back of another filling every part with their 
stench, sow the seeds of pestilence and death. 

And the city will be of a beauty equal to its name, and useful to you 
for its revenues and the perpetual fame of its growth. 

The municipality of Lodi will bear the expense, and keep the 
revenue which once a year it pays to the Duke. 

To the stranger who has a house in Milan it will often befall that in 
order to be in a more imposing place he will go and live in his own 
house; and whoever is in a position to build must have some store of 
wealth, and in this way the poor people will become separated by such 
settlers, and when these . . . assessments will increase and the fame 
of its greatness. And even if he should not wish to reside in Milan 
he will still remain faithful, in order not to lose the profit of his house 
at the same time as the capital. c.a. 65 v. b 

[Architectural drawings: ground plans] 

Buttery. Kitchen. Family. 

He who is stationed in the buttery ought to have behind him the 
entrance to the kitchen, in order to be able to do his work expedi- 
tiously; and the window of the kitchen should be in the front of the 
buttery so that he may extract the wood. 

The drawing that I have made has a larger facade behind than in 
front, whereas it should be the opposite. 

The large room for the family away from the kitchen, so that the 
master of the house may not hear their clatter; and the kitchen may 
be convenient for washing the pewter so that it may not be seen being 
carried through the house. 

1 Words crossed out in MS. 



Large room for the master. Room. Kitchen. Larder. Guard Room. 
Large room for the family. 

Larder, logs, kitchen and hen-coop (? pollaro) and hall, and the 
apartment will be or ought to be in contact for the convenience that 
ensues; and the garden and stable, manure and garden, in contact. 
The large room for the master and that for the family should have 
the kitchen between them, and in both the food may be served 
through wide and low windows, or by tables that turn on swivels. 

The wife should have her own apartment and hall (sala) apart from 
that of the family, so that she may set her serving-maids to eat at an- 
other table in the same hall. She should have two other apartments as 
well as her own, one for the serving-maids the other for the wet 
nurses, and ample space for their utensils. 

I wish to have one door to close the whole house. c.a. 158 v. a 

The hall for the festival should be situated so that you come first 
into the presence of the lord, and then of the guests, and the passage 
should be so arranged that it enables you to enter the hall without 
passing in front of the people more than one may wish; and over on 
the other side opposite to the lord should be situated the entrance of 
the hall and a convenient staircase, which should be wide, so that the 
people in passing along them may not push against the masqueraders 
and damage their costumes, when going out . . . the crowd of men 
. . . with such masks . . . this hall . . . two rooms side by side . . . 
right double ... of this an exit . . . collection and one for the 
masqueraders. c.a. 214 r. b 

[A plan for laying out a water-gar -den] 

The staircase is one braccio and three quarters wide and it is bent 
like a knee, and altogether it is sixteen braccia with thirty two steps 
half a braccio wide and a quarter high; and the landing where the 
staircase turns is two braccia wide and four long, and the wall which 
divides one staircase from the other is half a braccio; but the breadth 
of the staircase will be two braccia and the passage half a braccio 
wider; so that this large room will come to be twenty-one braccia 
long and ten and half braccia wide, and so it will serve well; and let 
us make it eight braccia high, although it is usual to make the height 
tally with the width; such rooms however seem to me depressing for 



they are always somewhat in shadow because of their great height, 
and the staircases would then be too steep because they would be 

By means of the mill I shall be able at any time to produce a current 
of air; in the summer I shall make the water spring -up fresh and 
bubbling, and flow along in the space between the tables, which will 
be arranged thus [draiving]. The channel may be half a braccio wide, 
and there should be vessels there with wines always of the freshest, 
and other water should flow through the garden, moistening the 
orange trees and citron trees according to their needs. These citron 
trees will be permanent, because their situation will be so arranged that 
they can easily be covered over, and the warmth which the winter 
season continually produces will be the means of preserving them far 
better than fire, for two reasons: one is that this warmth of the 
springs is natural and is the same as warms the roots of all the plants; 
the second is that the fire gives warmth to these plants in an accidental 
manner, because it is deprived of moisture and is neither uniform nor 
continuous, being warmer at the beginning than at the end, and very 
often it is overlooked through the carelessness of those in charge of it. 

The herbage of the little brooks ought to be cut frequently so that 
the clearness of the water may be seen upon its shingly bed, and only 
those plants should be left which serve the fishes for food, such as 
watercress and other plants like these. 

The fish should be such as will not make the water muddy, that is to 
say eels must not be put there nor tench, nor yet pike because they 
destroy the other fish. 

By means of the mill you will make many water-conduits through 
the house, and springs in various places, and a certain passage where, 
when anyone passes, from all sides below the water will leap up, and 
so it will be there ready in case anyone should wish to give a shower- 
bath from below to the women or others who shall pass there. 

Overhead we must construct a very fine net of copper which will 
cover over the garden and shut in beneath it many different kinds of 
birds, and so you will have perpetual music together with the scents of 
the blossom of the citrons and the lemons. 

With the help of the mill I will make unending sounds from all 



sorts of instruments, which will sound for so long as the mill shall 
continue to move. c.a. 271 v. a 

[The dimensions of a temple] 

You ascended by twelve flights of steps to the great temple, which 
is eight hundred feet in circumference and is built in the shape of an 
octagon. At the eight corners were eight large plinths a braccio and a 
half in height and three in width and six in length at the base, with an 
angle in the centre which served as the foundation for eight large 
pillars that rose to a height of twenty-four braccia above the base of the 
plinth, and on top of these stood eight capitals three braccia each [in 
length] and six wide. Above these followed architrave, frieze and 
cornice, four braccia and a half in height, carried on in a straight line 
from one pillar to another, and thus it surrounded the temple with a 
circuit of eight hundred braccia; between each of the pillars, as a 
support to this entablature, there stood ten large columns of the same 
height as the pillars, three braccia thick above their bases which were 
one braccio and a half in height. 

You ascended to this temple by twelve flights of steps, the temple 
being upon the twelfth, built in the shape of an octagon, and above 
each angle rose a large pillar, and between the pillars were interposed 
ten columns of the same height as the pillars, which rose twenty-eight 
and a half braccia above the pavement. At this same height were placed 
architrave, frieze and cornice, which formed a circuit round the temple, 
eight hundred braccia in length and of uniform height. Within this 
circuit at the same level towards the centre of the temple at a distance 
of twenty-four braccia rise pillars and columns, corresponding to the 
eight pillars of the angles and the columns placed in the facade. And 
they rise to the same height as those already mentioned, and above 
these pillars the continuous architrave goes back towards the pillars 
and columns first spoken of. c.a. 285 r. c 

Our ancient architects or such . . . commencing first of all with the 
Iti, who according to the discourses of Diodorus Siculus were the first 
builders and constructors of great cities, and of fortresses and buildings 
both public and private which had distinction, nobility and grandeur; 
and by reason of this their predecessors beheld with amazement and 



stupefaction the lofty and immense engines which seemed to them . . . 

c.a. 325 r. b 

An inverted arch is better for making a support than an ordinary 
one, because the inverted arch finds a wall below it which resists its 
weakness, while the ordinary arch finds where it is weakest nothing 
but air. Tr. 13 a 


An arch is nothing other than a strength caused by two weaknesses; 
for the arch in buildings is made up of two segments of a circle, and 
each of these segments being in itself very weak desires to fall, and as 
the one withstands the downfall of the other the two weaknesses are 
converted into a single strength. 



When once the arch has been set up it remains in a state of equi- 
librium, for the one side pushes the other as much as the other pushes 
it; but if one of the segments of the circle weighs more than the other 
the stability is ended and destroyed, because the greater weight will 
subdue the less. a 50 r. 

[With architectural drawing and plan] 

Ground plan of the pavilion which is in the middle of the labyrinth 
of the duke of Milan. 

Pavilion of the garden of the duchess of Milan. 1 


\ With plan and drawing of fortification] 


With this square bastion you should make only two towers in order 
that having . . . that one may not impede the other; and at each tower 
you should make a bridge entering into the ravelin as is shown in the 

1 A document recently found at Como bearing the date March 28, 1490, consists of a 
contract for the supply of stone for a pavilion which 'Maestro Lionardo painter and 
architect' was to construct in Milan. 



drawing. The diameter of the square bastion should be a hundred 
braccia, and the diameter of each tower should be thirty braccia. 

The ravelins should be open within so that being so the enemy 
cannot maintain himself there, but is exposed to attack from the towers. 

b 12 r. 
[With architectural drawing} 

If you have your family in your house, make their habitations in 
such a way that at night neither they nor the strangers to whom you 
give lodging are in control of the egress of the house; in order that 
they may not be able to enter in the habitation where you live or sleep, 
close the exit m, and you will have closed the whole house, b 12 v. 

[With drawing of section of wall of a house] 

C is a stove which receives heat from the kitchen chimney by means 
of a copper flue two braccia high and one wide, and a stone is put 
over the place in summer in order that it may be possible to use the 
stove; b will be the place for keeping salt, and at the division a there 
will be an opening of a passage into the chimney for hanging up salted 
meats and such like things; and in the ceiling there will be many flues 
for the smoke, with different exits at the four sides of the chimney, so 
that if the north wind should begin to be troublesome the smoke may 
find an outlet on the other side. And the smoke proceeds to spread it- 
self through the numerous flues and to cure salted meats; tongues and 
sausages and things like these it brings to perfection. But see to it that 
when you push the small door a a window opposite opens, which gives 
light to the little room; and this will be done by means of a rod joined 
to the door and the window in this way. b 14 v. 

[With ground plan of fortress] 

A way of a fortress with double moat. And the spurs which pass 
from the principal wall to the Garland serve two uses: that is they 
form a buttress and they help in part to render it possible to defend the 
base of the Garland when the principal wall has been thrown down. 

b 15 r. 

[Note with plan of section of town showing high- and low-level roads] 

The roads [marked] m are six braccia higher than the roads 

[marked] p s, and each road ought to be twenty braccia wide and have 



a fall of half a braccio from the edges to the centre. And in this centre 
at every braccio there should be an opening one braccio long and of 
the width of a finger, through which rain-water may drain off into 
holes made at the level of the roads p s. And on each side of the ex- 
tremity of the width of this road there should be an arcade six 
braccia broad resting on columns. And know that if anyone wishes 
to go through the whole place by the high-level roads, he will be able 
to use them for this purpose, and so also if anyone wishes to go by the 
low-level roads. 

The high-level roads are not to be used by waggons or vehicles such 
as these but are solely for the convenience of the gentlefolk. All carts 
and loads for the service and convenience of the common people should 
be confined to the low-level roads. 

One house has to turn its back on another, leaving the low-level 
road between them. The doors n serve for the bringing in of provisions 
such as wood and wine and suchlike things. The privies, the stables 
and suchlike noisome places are emptied by underground passages, 
situated at a distance of three hundred braccia from one arch to the 
next, each passage receiving its light through the openings in the streets 
above. And at every arch there should be a spiral staircase; it should be 
round because in the corners of square ones nuisances are apt to be 
committed. At the first turn there should be a door of entry into the 
privies and public urinals, and this staircase should enable one to de- 
scend from the high-level to the low-level road. 

The high-level roads begin outside the gates, and when they reach 
them they have attained a height of six braccia. The site should be 
chosen near to the sea or some large river, in order that the impurities 
of the city which are moved by water may be carried far away. 

b 16 r. and 15 v. 
[ Architectural} 

The earth which is dug out from the cellars ought to be raised at 
one side so as to construct a terrace garden at the same level as the hall; 
but see that between the earth of the terrace garden and the wall of the 
house there is an intervening space, so that damp may not spoil the 
principal walls. b 19 v. 



[With drawing and ground plan of church] 

This edifice is inhabited both in the upper and in the lower part. 
The entrance to the upper part is by way of the campaniles, and it goes 
along the level on which rest the four drums of the dome, and the said 
level has a parapet in front of it. And none of these drums communi- 
cates with the church but they are entirely separate. b 24 r. 

Let the street be as wide as the universal height of the houses. 

b 36 r. 
f Castle of Milan ] 
[ With drawing] 

The moats of the castle of Milan within the Garland are thirty 
braccia; the ramparts are sixteen braccia high and forty wide, and this 
is the Garland. 

The outer walls are eight braccia thick and forty high, and the inner 
walls of the castle are sixty braccia, which would please me entirely if 
it were not that I should wish to see that the bombardiers who are in 
the walls of the Garland do not issue forth in the secret inner way, that 
is in S y but lower themselves one at a time as appears in m f. 

Since good bombardiers always aim at the embrasures of fortresses, 
and can if they break a single embrasure in the said Garland enter like 
cats through this breach and make themselves masters of all the towers, 
walls, and secret passages of the Garland, therefore if the embrasures 
are m f and it shall come about that a mortar bursts one of these em- 
brasures and the enemy enters within, they will not be able to pass 
farther but may be beaten back and driven away by a soldier stationed 
in the machicolations above; and the passage / ought to be continued 
through all the walls from three quarters downwards and without hav- 
ing any exit above, either in the walls or the towers, except that by 
which one enters, which will have its beginning within the fortress; 
and the above-mentioned secret passage / ought not to have any air- 
hole on the outside but to get its light on the side of the fortress 
through the frequent loopholes. b 36 v. 


[With drawing] 
The way in which one should construct a stable: you will first di- 



vide its width in three parts, its length does not matter; and these three 
divisions should be equal, each being six braccia wide and ten high. 
The centre part should be for the use of the master of the stable, the 
two at the sides for the horses, each requiring for width three braccia 
and for length six braccia, and being half a braccio higher in front than 

The manger should be two braccia from the ground, the beginning 
of the rack three braccia, and the top of it four braccia. 

To attempt however to keep my promise, namely to make the said 
place contrary to the usual custom clean and neat: as to the upper 
portion of the stable, that is, where the hay is, this part should have at 
its outer end a window six [" ? braccia] high and six wide, by which 
hay can easily be brought up to the loft as is shown in the machine E\ 
and this should be erected in a place six braccia in breadth and as long 
as the stable, as is shown in K p. The other two parts, which have the 
first between them, are each divided into two parts. The two towards 
the hay are four braccia, and are entirely for the use and passage of the 
stable attendants; the other two which extend to the outside walls are 
two braccia, as is shown in S R, and these are for the purpose of giving 
the hay to the manger, by means of funnels narrow at the top, and 
broad above the mangers, so that the hay may not be stopped on the 
way. They should be well plastered and cleaned, as they are repre- 
sented where it is marked 4 / s. In order that the horses may be given 
water the troughs should be of stone, so made as to be able to be un- 
covered as are boxes by raising their lids. b 39 r. 

A building ought always to be detached all round in order that its 
true shape can be seen. p 39 v. 

[Drawing of castle showing staircases] 

Here are five staircases with five entrances; and one is not visible to 
another and when anyone is in one he cannot go into another; and it is 
a good system for those who are maintained there, in that it prevents 
them from mingling with each other, and being separated they will be 
ready for the defence of the tower: this can be either round or square. 

b 47 r. 
[With drawing] 

Ten spiral staircases round a tower. b 47 v. 



[With plan of ravelin] 

The ramparts placed in front of the doors of the ravelin should be 
solid, except for the winding staircase placed in the centre in order to 
connect with the battlements above, and one enters into this staircase 
by subterranean passages. b 49 v. 

[With drawings] 
A represents the upper church of San Sepolcro at Milan. 
B is the part of it below the ground. b 57 r. 

[With drawing] 

Where you do not wish to have a portico round the whole of a 
courtyard, but that only one or two of the four sides should have the 
portico, make the others also with the same arrangement of columns, 
and surround the arches with an architrave on the inner side which de- 
scends as far as the bases of the columns. 

And make the windows within the said architraves, and in the same 
way place the chief beams within the rooms in such a manner as to 
come between one window and the other. b 67 v. 

[With drawing] 

Double staircase. One for the commander of the castle, the other 
for the garrison. b 68 v. 


Architraves of several pieces are stronger than those of merely one 
piece, if these pieces are so placed that their lengths point to the centre 
of the earth. This is proved from the fact that the stones have their 
marking, or vein, usually crosswise, that is in the direction of the 
opposite horizons of the same hemisphere, and this is the contrary to 
the vein, of plants which have. ... g 52 r. 

[Of arch and support] 

The continuous quantity bent by force into a curve pushes itself in 
the direction of the line into which it desires to return. h 35 v. 

That part of the continuous quantity will make a greater movement 
which is more distant from the part which moves less. 




That side of the support of which the upper part is the heavier will 
bend in a curve towards its centre. H 36 v. 

The sides of every defined quantity which has been raised in a 
pyramidal heap will be of the slant of the angular diameter of the 
perfect square. h 37 r. 

[For decorating a room] 

The narrow moulding at the top of the room — thirty lire. 

For the moulding below this, I reckon each panel at seven lire, and, 
in expenses on azure, gold, white-lead, gypsum, indigo and size, three 
lire; time — three days. 

The subjects under these mouldings with their pilasters, twelve lire 
for each. 

I estimate the cost of enamel, azure and gold, and other colours at 
one lira and a half. 

I allow five days for studying the composition, the small pilaster and 
other things. 

Item for each small arch — seven lire. 

Cost of azure and gold — three and a half lire. 

Time — four days. 

For the windows — one and a half lire. 

The large cornice below the windows — sixteen soldi the braccio. 

Item for the Roman historical compositions — fourteen lire each. 

The philosophers — ten lire. 

The pilasters — one ounce of azure, ten soldi. 

For gold — fifteen soldi. 

I estimate [this azure and gold] at two and a half lire. 

h 125 [18 v.] r. and 124 [19 r.] v. 

[Drawing of church with section of ground plan] 

Both lower and upper part of this edifice are usable, as in San 
Sepolcro, and it is similar in its upper and lower parts except that the 
upper part has the cupola c d and the lower the cupola a b. As you 
enter the lower church you descend ten steps, and when you go up into 
that above you ascend twenty steps, which reckoning each as a third 
of a braccio comes to ten braccia. This then is the distance there is 
between the level of the one church and of the other. 

ms. 2037 Bib. Nat. 4 r. 



[With architectural drawing] 

Here a campanile neither can nor ought to be made. 

Rather must it stand separate, as it does in the cathedral, or at San 
Giovanni in Florence; and so also the cathedral at Pisa, for there the 
campanile may be seen by itself round in shape and standing apart, 
as also is the cathedral. And each by itself can reveal its perfection. 

If however anyone should desire to make it part of the church he 
should make the lantern-tower serve as a campanile, as it does in the 
church of Chiaravalle. ms. 2037 Bib. Nat. 5 v. 

Mills should not be built by stagnant water, nor by the side of the 
sea, because the storms choke up with sand every canal that is made 
upon its shores. b.m. 63 v. 


The first and most essential requisite is stability. 

As regards the foundations of the component parts of temples and 
other public buildings, their depths should bear the same relation one 
to another as do the weights which are to rest upon them. 

Each section of the depth of the earth in a given space is arranged 
in layers, the layers having each a heavier and a lighter part, the heavier 
being at the bottom. 

This comes from the fact that these layers are formed by the sedi- 
ment from the water discharged into the sea by the current of the 
rivers which are poured into it. 

The heaviest part of this sediment was the part that was discharged 
first, and this process continued. 

And this is the action of the water when it becomes stationary, and 
it is carrying it away at first where it moves. 

These layers of soil are visible in the banks of rivers which in their 
continuous course have sawn through and divided one hill from an- 
other in a deep defile, wherein the level of the waters has receded from 
the shingle of the banks, and this has caused the substance to become 
dry and to be changed to hard stone, especially such mud as was of 
the finest texture. And this leads us to conclude that each part of the 
earth's surface was once the centre of the earth, and so conversely. 




A wall will always crack when it does not dry uniformly at the same 

A wall of uniform thickness does not all become dry at the same 
time unless it is in contact with an equal medium; thus if a wall be so 
built that part of it touches a damp mound while the rest is exposed 
to the atmosphere, this latter part will become somewhat contracted 
while the damp portion will retain its original size. 

For the part which becomes dried by the atmosphere draws itself 
together and shrinks, and the part in contact with the damp does not 
become dry, and the dry part readily breaks away from the damp part 
as this has not the coherence necessary for it to follow the movement 
of the part that is in process of becoming dry. 


Those arched cracks wide above and narrow below have their 
origin in walled-up doorways, which contract more in length than in 
width in proportion as their height is greater than their breadth, and 
as the joins of the mortar are more numerous in the height than in 
the breadth. b.m. 138 r. 

When either a complete dome or a half dome is vanquished above by 
an insupportable weight, the vault will burst asunder, the crack being 
small in the upper part and broad below, and narrow on the inner side 
and wide on the outer side, after the manner of the skin of a pome- 
granate or orange which splits into many parts lengthwise, for the 
more it is pressed upon from the opposite ends, the wider asunder will 
those parts of the joints open which are farthest away from the cause 
of the pressure. And for this reason the arches of the vaults of any apse 
should never be loaded more than the arches of the building of which 
it forms a part, especially because that which weighs most presses most 
heavily upon the parts below it and drives them down upon their 
foundations; but this cannot happen with lighter things such as the 
aforesaid apses. b.m. 141 v. 



Make first a treatise of the causes which bring about the collapse of 
walls, and then, separately, a treatise of the remedies. 

Parallel cracks are constantly appearing in buildings erected in moun- 
tainous places where the rocks are stratified and the stratification runs 
obliquely, for, in these oblique seams, water and other moisture often 
penetrates, bearing with it a quantity of greasy and slimy earth; and 
since this stratification does not continue down to the bottom of the 
valleys the rocks go slipping down their slope, and never end their 
movement until they have descended to the bottom of the valley, car- 
rying with them after the manner of a boat such part of the building 
as they have severed from the rest. 

The remedy for this is to build numerous piers under the wall which 
is slipping away, with arches from one to another, and well-rooted [ P] 1 
[ Pbuttressed] and let the pillars have their bases firmly set in the strati- 
fied rock so that they may not break away. 

In order to find the immovable part of the aforesaid stratum, it is 
necessary to sink a shaft through it to a great depth beneath the foot of 
the wall, and in this shaft to polish a smooth surface of the breadth of 
a hand from the top to the bottom of the side on which the hill slopes 
down. At the end of some time this smooth portion made on the side of 
the shaft will show very plainly which part of the mountain is moving. 

b.m. 157 r. 


Stones which are built up with an equal number from bottom to top 
and laid with an equal quantity of mortar, will settle down equally as 
the moisture which softens the mortar evaporates. 

Cracks in walls will never be parallel unless the part of the wall 
which is separated from the rest does not descend. 


Stability of buildings results from a law the converse of the two fore- 
going, namely that the walls should be built up all equally in equal 

1 MS. abarbanati. 



stages, which should embrace the whole circuit of the building and the 
total thickness of the walls no matter of what kind; and although the 
thin wall dries more rapidly than a thick one it will not have to break 
as the result of the weight which it may acquire from one day to an- 
other; for if a double quantity of it were to dry in one day, a wall of 
double the thickness would dry in two days or thereabouts, and so a 
slight difference in weight would be balanced by a slight difference 
of time. 


When the crack in a wall is wider at the top than at the bottom it is 
a clear sign that the source of the destruction of the wall lies outside 
the perpendicular of the crack. b.m. 157 v. 


Walls collapse as a result of cracks which are either vertical or slant- 
ing. Cracks which proceed vertically are caused by new walls being 
built in conjunction with old walls either vertically or with toothings 
fitted into the old walls; for as these toothings cannot offer any resist- 
ance to the insupportable weight of the wall joined on to them they 
must needs break and allow the new wall to settle down, in which 
process it will sink a braccio in every ten, or more or less according to 
the greater or smaller quantity of mortar used for the stones in the 
construction, and whether the mortar is very liquid or not. And remem- 
ber always to build the walls first and then add the facing stones, 
because unless this is done, since the subsidence of the wall in settling 
will be greater than that of the outer shell, the toothings set in the sides 
of the wall will necessarily be broken, because the stones used for facing 
the walls being larger than the stones used in their construction will of 
necessity take a less quantity of mortar in their joints, and therefore the 
subsidence will be less. But this cannot happen if the facing of the wall 
is added after the wall has had time to dry. b.m. 158 r. 




[With diagrams] 

Let the houses be transported and arranged in order, and this can be 
done with ease because these houses are first made in parts upon the 
open places, and are then fitted together with their timbers on the spot 
where they are to remain. 

Let fountains be made in each piazza. 

Let the countryfolk dwell in parts of the new houses when the court 
is not there. b.m. 270 v. 

Cover of the preaching place of the castle. Forster 11 70 v. 

That angle will have the greatest power of resistance which is most 
acute, and the most obtuse will be the weakest. Forster 11 87 v. 


[With drawing] 

Here it is shown how the arches made in the sides of the octagon 
push the columns of the angles outwards, as is shown in the line h c 
and in the line t d, which push the column m outwards, that is they 
exert pressure to drive it from the centre of this octagon. 

Forster n 93 r. 

That part of the bulk of the lower support will be more weighed 
down upon which is nearer the centre of the weight supported by it. 

Forster in 13 v. 

That in the canals nothing be thrown, and that these canals go 
straight to the houses. Forster in 23 v. 

The hall of the court is one hundred and twenty-eight steps long and 
its breadth is twenty-seven braccia. Forster in 49 v. 


The height of the walls of the courtyard should be half its length, 
that is if the courtyard be forty braccia the house ought to be twenty 




high in the walls of the said courtyard, and this courtyard should be 
half the width of the whole front. Windsor: Drawings 12585 v. 

[ Water -st air in the Sforzesea] 

When the descent from the floodgates has been so hollowed out that 
at the end of its drop it is below the bed of the river, the waters which 
descend from them will never form a cavity at the foot of the bank, 
and will not carry away soil in their rebound, and so they will not 
proceed to form a fresh obstacle but will follow the transverse course 
along the length of the base of the floodgate from the under side. 
Moreover if the lowest part of the bank which lies diagonally across the 
course of the waters be constructed in deep broad steps after the man- 
ner of a staircase, the waters which as they descend in their course are 
accustomed to fall perpendicularly from the beginning of this lowest 
stage, and dig out the foundations of the bank, will not be able any 
longer to descend with a blow of irresistible force. 

And I give as an example of this the stair down which the water falls 
from the meadows of the Sforzesea at Vigevano, for the running water 
falls down it for a height of fifty braccia. Leic. 21 r. 

[With drawing] 

Stairs of Vigevano, below the Sforzesea, with one hundred and thirty 
steps a quarter of a braccio high and half a braccio wide, down which 
the water falls without wearing away anything as it finishes its fall; 
and by these stairs so much soil has come down as to have dried up a 
swamp, that is by having filled it up; and it has formed meadows from 
swamps of great depth. Leic. 32 r.