Owing to my persevering researches I had nothing left to learn in conjuring; but, in order to carry out my scheme, I had to study the principles of a science on which I greatly depended for the success of my future performances. I allude to the science, or rather art, of making automata. While occupied with this idea I made active investigations; I applied to the public libraries and their keepers, whom my tenacious importunity drove into despair. But all the information I collected only brought me descriptions of mechanical toys, far less ingenious than certain playthings of the present day, or absurd statements of chefs-d’œuvre published in the dark ages. My readers may judge from the following: I found, in a work bearing the title “Apologie pour les Grands Homines Accusés de Magie,” that “Jean de Montroyal presented to the Emperor Charles V. an iron fly, which made a solemn circuit round its inventor’s head, and then reposed from its fatigue on his arm.” Such a fly is rather extraordinary, yet I have something better to tell my readers--still about a fly. Gervais, Chancellor to the Emperor Otho III., in his book entitled “Otia Imperatoris,” informs us that “the sage Virgilius, Bishop of Naples, made a brass fly, which he placed on one of the city gates, and that this mechanical fly, trained like a shepherd’s dog, prevented any other fly entering Naples; so much so, that during eight years the meat exposed for sale in the market was never once tainted.” How much should we regret that this marvellous automaton has not survived to our day? How the butchers, and still more their customers, would thank the learned bishop! Pass we to another marvel: Francis Picus relates that “Roger Bacon, aided by Thomas Bungey, his brother in religion, after having rendered their bodies equal and tempered by chemistry, employed the Speculum Amuchesi to construct a brazen head which should tell them if there were any mode of enclosing the whole of England by a high wall. They forged at it for seven years without relaxation, but misfortune willed it that when the head spoke the two monks did not hear it, as they were engaged on something else.” I have asked myself a hundred times how the two intrepid blacksmiths knew the head had spoken, when they were not present to hear it. I never discovered any other solution than this: it was, doubtlessly, _because their bodies were equalized and tempered by chemistry_. But here is a far more astounding marvel. Tostat, in his “Commentaires sur l’Enode,” states that “Albertus Magnus, Provincial of the Dominicans, at Cologne, constructed a brass man, which he worked at continually for thirty years. This work was performed _under various constellations_ and _according to the laws of perspective_.”