From: Leonardo da Vinci
To: Ludovico Sforza
Date: sometime around 1483/84
Subject: court employment application
Content-Type: text/parchment

My Most Illustrious Lord, 

Having now sufficiently seen and considered the achievements of all
those who count themselves masters and artificers of instruments of
war, and having noted that the invention and performance of the said
instruments is in no way different from that in common usage, I shall
endeavour, while intending no discredit to anyone else, to make myself
understood to Your Excellency for the purpose of unfolding to you my
secrets, and thereafter offering them at your complete disposal, and
when the time is right bringing into effective operation all those
things which are in part briefly listed below:

1. I have plans for very light, strong and easily portable bridges
with which to pursue and, on some occasions, flee the enemy, and
others, sturdy and indestructible either by fire or in battle, easy
and convenient to lift and place in position. Also means of burning
and destroying those of the enemy.

2. I know how, in the course of the siege of a terrain, to remove
water from the moats and how to make an infinite number of bridges,
mantlets and scaling ladders and other instruments necessary to such
an enterprise.

3. Also, if one cannot, when besieging a terrain, proceed by
bombardment either because of the height of the glacis or the strength
of its situation and location, I have methods for destroying every
fortress or other stranglehold unless it has been founded upon a rock
or so forth.

4. I have also types of cannon, most convenient and easily portable,
with which to hurl small stones almost like a hail-storm; and the
smoke from the cannon will instil a great fear in the enemy on account
of the grave damage and confusion.

5. Also, I have means of arriving at a designated spot through mines
and secret winding passages constructed completely without noise, even
if it should be necessary to pass underneath moats or any river.

6. Also, I will make covered vehicles, safe and unassailable, which
will penetrate the enemy and their artillery, and there is no host of
armed men so great that they would not break through it. And behind
these the infantry will be able to follow, quite uninjured and
unimpeded.

7. Also, should the need arise, I will make cannon, mortar and light
ordnance of very beautiful and functional design that are quite out of
the ordinary.

8. Where the use of cannon is impracticable, I will assemble
catapults, mangonels, trebuckets and other instruments of wonderful
efficiency not in general use. In short, as the variety of
circumstances dictate, I will make an infinite number of items for
attack and defence.

9. And should a sea battle be occasioned, I have examples of many
instruments which are highly suitable either in attack or defence, and
craft which will resist the fire of all the heaviest cannon and powder
and smoke.

10. In time of peace I believe I can give as complete satisfaction as
any other in the field of architecture, and the construction of both
public and private buildings, and in conducting water from one place
to another.

Also I can execute sculpture in marble, bronze and clay. Likewise in
painting, I can do everything possible as well as any other, whosoever
he may be.

Moreover, work could be undertaken on the bronze horse which will be
to the immortal glory and eternal honour of the auspicious memory of
His Lordship your father, and of the illustrious house of Sforza.

And if any of the above-mentioned things seem impossible or
impracticable to anyone, I am most readily disposed to demonstrate
them in your park or in whatsoever place shall please Your Excellency,
to whom I commend myself with all possible humility.