you.

genius of almost universal powers that I wish to bring him before Of the first forty years of his life very little accurate knowledge is available -indeed, not much more than I have sketched in above. He was thirty-two years of age when he left Florence for Milan. There is some reason to suppose that in the meantime he had spent at least three years in Eastern travel, during which he visited Egypt, Constantinople, and Armenia. Richter ingeniously brings forward in support of this story the numerous allusions to the East which are to be found in his writings. In a manuscript in the British Museum there is an allusion to the eruptions of Etna and Stromboli; in the library at Windsor Castle a description of the Island of Cyprus one of the MSS. in the Institut de France has the design of a bridge to unite Pera with Constantinople; the Codex Atlanticus at Milan bears a still more convincing testimony in the shape of a draft letter to the Diodario (the Deratdar) of Syria, in which he recites the work undertaken for the Sultan of Babylon, the name often given in the Middle Ages to Cairo. "Here am I," writes Leonardo, "in Armenia to carry out with devotion the work with which you entrusted me when you sent me hither. To begin with the districts which appear to be most suitable I went to the town of Chalendra. It is a town close to our frontier at the foot of the Taurus range," &c. &c. Again, “I do not deserve the charge of idleness, O Diodario, as your reproaches seem to suggest; but rather as your kindness which is boundless has created the office entrusted to me, I feel bound to make

experiments and to make researches into the reason of such considerable and stupendous effects"-the allusion being to the damage done by a hideous earthquake, the "grande e stupendo effecto" of which the Sultan had himself witnessed on a journey in 1477. In the face of this evidence one would think that there could be little doubt that Leonardo did actually undertake this journey, and that he was employed as an engineer by the Sultan Kait Bai. It is but fair to say, however, that writers so eminent as Muntz, Séailles, and Govio, hinting that the letters were part of a romance which Leonardo projected but never finished, receive the story only with the greatest reservation; for myself I have thought it to be at least of sufficient interest to be mentioned this evening, especially as it concerns the scientific and mechanical side of our hero's capabilities-the object being nothing less than the reconstruction of a city which had been flooded by the collapse of a mountain damming up a river.

Florence at the end of the fifteenth century was a fitting cradle for the development of Leonardo's special scientific genius. Art, industry, commerce, and finance flourished amazingly, and the acquisition by purchase of Leghorn from the Genoese gave the Florentine merchants and manufacturers facilities for the inlet of raw materials and the export of their finished wares. Cloth factories, the weaving of gold and silver brocade, dyes the secrets of which were a jealously guarded state monopoly, were among the chief industrial products. Machinery at work everywhere, a fever of commercial activity-what a stimulus must these

surroundings have been to such a mind as Leonardo's! It was, as Hermann Grothe says, "the age of Pericles returned once more."

The

He

rattle and din of machinery were dear to Leonardo's heart-mechanics were to him, as he said himself, "the Paradise of sciences by the aid of which we reach the fruit of mathematics," and so we find him scheming, planning, inventing. At one moment he is designing a lighthouse; at another he is deeply absorbed in plans for making the Arno navigable, for converting it into a sort of Manchester Ship Canal. Hydrostatics, water, the waves of the sea, offer problems which enchant him. perceives the power of steam, and tries to apply it as a motive power to boats and pumps he constructs a steam gun, the invention of which, for some unknown and perfectly mythical reason, he attributes to Archimedes: he turns a roasting spit by the hot air of the chimney: he invents an instrument for planing and another for boring wooden pipes: his saw is still used at the quarries of Carrara : he makes cranes, levers, a weaving machine, a rain gauge he discovers the topsyturvydom of the camera obscura: his studies in artillery, including a movable breech, are marvellous optics engross him. He does not invent the telescope, but he sees the moon through a lens. a lens. Nothing is too great, nothing too small to occupy his attention. But perhaps his most absorbing experiments were those upon aviation, and in view of the progress which within the last few years has been made in that direction they are of supreme interest to-day. For thirty years, at Milan first and afterwards at

Rome, he laboured at making a flying machine. He invented a parachute, and although the Montgolfier balloon was not invented until the end of the eighteenth century he had discovered the principle-for Vasari tells us that he was in the habit of making figures of animals in a thin waxen film which, when he had inflated them with hot air, floated about aloft to the great amusement of his friends. But Leonardo was much too keen-sighted not to perceive that it was not by using a machine lighter than itself, not by balloons or parachutes, that the air was to be conquered. If he did not succeed in his great endeavour, he at any rate perceived that if man is to fly it must be by some means similar to those with which the bird is endowed. The flight of the eagle poised in the air, the arrangement of the joints and feathers in the wing, all these were carefully observed and imitated, all that was wanting was the motor: he had only the muscles of the flying man himself upon which to depend, and so he failed. But with what a frenzy of excited interest he would have watched the evolutions of an aeroplane of to-day! The goal of his dreams, of the long endeavours of thirty years, reached at last! Man the Master of the Air!

It would not be possible, within the limits of the time that I must give myself, to go more deeply into Leonardo's mechanical work. He invented many things and made many improvements in the work of others. Whatever he did was distinguished by delicacy and lightness far ahead of the clumsy work of some of those who followed him.

Leonardo was thirty years of age when, in 1483, Lorenzo the Magnificent sent him to Milan with a present of a lute for Lodovico Sforza il Moro, who was at that time at the height of his power. There are several versions of the story of his mission. We need not concern ourselves with them. It is enough for us that he went, and that he afterwards offered his services to the Duke in a letter which is of the greatest interest, as giving his own estimate of his capabilities. Here is Richter's version :

"Having, most illustrious Lord, seen and duly considered the experiments of all those who repute themselves masters in the art of inventing instruments of war, and having found that their instruments differ in no way from such as are in common use, I will endeavour, without wishing to injure any one else, to make known to Your Excellency certain secrets of my own as briefly

enumerated here below.

"1. I have a way of constructing very light bridges, most easy to carry, by which the enemy may be pursued and put to flight. Others also of a stronger kind, that resist fire or assault, and are easy to place and to remove. I know ways also for burning and destroying those of the enemy.

"2. In case of investing a place I know how to remove the water from ditches and to make various scaling ladders, and other such instruments.

3. Item: If, on account of the height or strength of a position, the place cannot be bombarded, I have a way for ruining every fortress which is not on stone foundations.