IV
Dürer's last years were given more and more to writing down his ideas for the sake of those who, coming after him, would, he was persuaded, go on far before him in the race for perfection. In 1525 he published his first book--"Instruction in the Measurement with the Compass, and Rules of Lines, Surfaces, and Solid Bodies, drawn up by Albert Dürer, and printed, for the use of all lovers of art, with appropriate diagrams." It contains a course of applied geometry in connection with Euclid's Elements. Dürer states from the very commencement that "his book will be of no use to any one who understands the geometry of the 'very acute' Euclid; for it has been written only for the young, and for those who have had no one to instruct them accurately." Thausing tells us his work shows certain resemblances to that of Luca Pacioli, a companion of Leonardo's, who may have been the "man who is willing to teach me the secrets of the art of perspective," and whom Dürer in 1506 travelled from Venice to Bologna to see; it is even possible that he saw Leonardo himself in the latter town. In 1527 he issued an essay on the "Art of Fortification," which the development of artillery was then transforming; and authorities on this very special science tell us that Dürer is the true author of the ideas on which the "new Prussian system" was founded. It was dread of the unchristian Turk who was then besieging Vienna which called forth from Dürer this excursion. He dedicated it in the following terms:
To the most illustrious, mighty prince and lord, Lord Ferdinand, King of Hungary and Bohemia, Infant of Spain, Archduke of Austria, Duke of Burgundy and Brabant, Count of Hapsburg, Flanders, and Tirol, his Roman Imperial Majesty, our most gracious Lord, Regent in the Holy Empire, my most gracious Sire.
Most illustrious mighty King, most gracious Sire,--During the lifetime of the most illustrious and mighty Emperor Maximilian of praiseworthy memory, your Majesty's Lord and Grandsire, I experienced grace and favour from his Imperial Majesty; wherefore I consider myself no less bound to serve your Majesty according to my small powers. As it happeneth that your Majesty has commanded some towns and places to be fortified, I am induced to make known what little I know about these matters, if perchance it may please your Majesty to gather somewhat therefrom. For though my theory may not be accepted in every point, still I believe something will arise from it, here and there, useful not to your Majesty only, but to all other Princes, Lords, and Towns, that would gladly protect themselves against violence and unjust oppression. I therefore humbly pray your Majesty graciously to accept from me this evidence of my gratitude, and to be my most gracious lord,
Your Royal Majesty's most humble
ALBRECHT DÜRER.
It seems that at any rate the Kronenburg Gate and Roseneck bastion of Strasburg were actually constructed in accordance with Dürer's method.
When, on April 6, 1528, Dürer died suddenly, two volumes of his great work on "Human Proportions" were ready for the press, and enough raw material, notes, drawings,&c., to enable his friend Pirkheimer to prepare and issue the remaining two with them. Of the misunderstanding of this the most important of Dürer's writings I shall say nothing here, as I have devoted a separate chapter to it.