In the first place, it is certain that the book itself, as well as the whole account, is not the production of Aristotle, for in all the writers who relate the actions of Alexander we do not find the least mention of such a horn. Secondly, it is not expressly said in that work that Alexander spoke through this horn, but only that he assembled his soldiers by it, which in past times was done by the sound of a trumpet, and at present is done both by trumpets and drums. It appears also that the author of the book, perhaps an Arabian, intended to give the reader an idea of a horn that had an uncommonly strong and loud sound. Thirdly, Kircher’s account and figure of the horn do not agree with that which Morhof found in the edition of Achillinus[230]. Lastly, none of these descriptions are such that an instrument to serve as a speaking-trumpet could be constructed from them. Wolf and other mathematicians are of opinion that the most advantageous form of a speaking-trumpet would be found with more certainty by experience than by theory. It may then be asked, whether any one ever caused such an instrument to be made from these descriptions. Kircher, who attempted things much more improbable, says he never tried it. Duhamel however relates that a Frenchman tried it, and discovered the real instrument[231]; but this information is of little weight, as it is much to be doubted that this Frenchman caused it to be made sufficiently exact according to the ancient description. I am as little acquainted with Bettini as Morhof; but I suspect that Duhamel meant Mar. Bettini, who, without making the smallest mention of Alexander’s horn, proposes only a tube, the one end of which should be applied to the mouth of a person who speaks, and the other to the ear of one who is dull of hearing[232]. This was rather an ear-trumpet than a speaking-trumpet, and it is certain that the former was invented before the latter. What we read in Porta, and what many think alludes to a speaking-trumpet, alludes evidently to an ear-trumpet only. That author infers, very justly, from the form of the ear, and particularly from that of the ears of those animals which are quick of hearing, that to hear at a distance one must apply to the ear a kind of wide funnel, as people to strengthen the sight use spectacles[233]. He asserts also, with equal truth, that one, through a long tube, can convey a whisper to the ear of another person at a very great distance[234]; an experiment which he himself made at the distance of two hundred paces. Schwenter, who wrote before the speaking-trumpet was known, proposes, from the hint of Porta, an ear-trumpet, one end of which should be applied to the ear[235].