Upon caterpillar tractors brought from America he proceeded to mount armored hulls built according to his own designs, the land battleships thus created being armed with both field and machine guns. They were tested under conditions of the greatest secrecy, the trials proving so successful that the construction of a considerable number was immediately authorized. In order that the public might obtain no hint of the true nature or purpose of these terrible new weapons they were referred to as “tanks,” the impression being given that they were intended for transporting water. Painted in dull colors and swathed in tarpaulins, fifty tanks were landed at Le Havre on August 29, 1916, and were moved up to the Somme front under cover of darkness. At dawn on September 15, everything being in readiness for the launching of the great Somme drive, they were entered in battle on a most astonished foe. Though I saw one of the tanks in action on this occasion—it was named, if I am not mistaken, “_Crème de Menthe_”—I was not permitted to photograph it or to write about it. It has repeatedly been asserted that these tanks were the first vehicles of their kind in the history of warfare, and that is true, so far as the method used for their propulsion is concerned, yet it is interesting to note that, ten years before the Great Navigator set foot on the beach of San Salvador, Leonardo da Vinci had written as follows to the Duke Ludovico Sforza: “I am also building secure and covered chariots which are invulnerable, and when they advance with their guns into the midst of the foe, even the largest army masses must retreat, and behind them infantry may follow in safety and without opposition.”