How to make a brazen or stone head, in the midst of a great field or garden, so artificial and natural, that though a man speak never so softly, and even whispers into the ear thereof, it will presently open its mouth, and resolve the question in French, Latin, Welsh, Irish, or English, in good terms, uttering it out of his mouth, and then shut it until the next question be asked. NOTE. Albertus Magnus, a celebrated philosopher of the thirteenth century, is said to have constructed an _automaton_ which not only performed all the apparent motions of life, but absolutely answered questions. It is recorded of Thomas Aquinas, that, having accidentally seen the head, he was so terrified that he broke it in pieces, upon which Albert exclaimed: _Periit opus triginta annorum_! Though this appears one of the earliest instances of a speaking automaton constructed by one of the laity, there is no doubt but that the method of conveying answers to various interrogatories, by the agency of concealed pipes or a speaking trumpet, was practised at a very early period. That the impostor Alexander, however, caused his Æsculapius to speak in this manner is expressly related by Lucan. He took, says this author, instead of a pipe, the gullet of a crane, and transmitted the voice through it to the mouth of the statue. But the invention of the _invisible girl_, which may be considered as an improvement on the oracular responses of the darker ages, infinitely surpassed any of those hitherto recorded. This very ingenious apparatus was publicly exhibited both at Bristol and in London for a considerable period, during which time no discovery was made of its internal mechanism; and it is probable that its construction would have remained a secret to all but the exhibitors, but for the ingenuity of Mr. (now Professor) Millington, who, in a course of Lectures delivered in the winter of 1806, explained the manner in which it was performed.