A History of Inventions, Discoveries, and Origins (Vol. 1&2). Johann Beckmann

Чтение книги онлайн.

СКАЧАТЬ the former, in the same manner as the latter, to a great distance, by means of an instrument. For this purpose, about twenty-four years before, he had caused to be constructed, in the Jesuits’ college at Rome, an ear-trumpet, through which the porter could communicate anything he had to say to him when he was in his apartment in the upper story. This apparatus attracted the notice of many strangers, who were astonished at its effect. He here represents it as a proper speaking-trumpet, and adds, that it excited much surprise, on account of the uncommon strength which it gave to the voice. For this reason he was very desirous of trying to what distance words could be distinctly conveyed by such a tube; and an opportunity occurred of doing this the same year that he wrote his Phonurgia. From a convent, situated on the top of a mountain, he assembled twelve hundred persons to divine service, at the distance of from two to five Italian miles, and read the Litany through it. Soon after, the emperor caused a tube to be made according to Kircher’s description, by which, without elevating the voice, he could be understood from Ebersdorf to Neugebeu. But though Kircher came so near to the invention of the speaking-trumpet, it does not appear certain by his works that he attempted or constructed it before Sir Samuel Morland. I shall now examine the evidences he adduces in his favour.

The most important of these is Schott, because he published his Magia Naturalis238 in 1657, before the invention of Sir Samuel Morland. All that is to be found in this work, however, relates alone to the ear-trumpet, a figure of which is added from the Musurgia; but we learn, with certainty, that Kircher then had the before-mentioned funnel or tube in his apartment. It is also not improbable that he had tried to answer the porter from his apartment, and that he had thereby remarked that the voice was strengthened; for it is not proved by Schott that he at that time was acquainted with and had in his possession a portable speaking-trumpet.

Another author by whom Kircher endeavours to support his claim is Harsdorfer; who, however, speaks only of tubes to be closely applied to the mouth and to the ear, and who refers to the Musurgia, without mentioning the real speaking-trumpet, though the second part of his Mathematical Recreations was first printed in 1677, and the third in 1692. Besides these testimonies, Kircher quotes also Eschinard concerning sound239. With that work I am not acquainted; but as the information it contains is taken from the Musurgia, it is of as little importance as that of Derham240, who refuses the invention to his countryman, and gives it to Kircher. When I unite all the evidence in favour of Kircher, it appears to be certain that he made known and employed the ear-trumpet earlier than the portable speaking-trumpet; that he, however, approached very near to the invention of the latter, but did not cause one to be constructed before Sir Samuel Morland, to whom the honour belongs of having first brought it to that state as to be of real use. Such, at least, is the manner in which this dispute is decided by the Jesuit De Lanis241.

When Morland’s invention was made known in France, it was pretended that Salar, an Augustine monk, had seven or eight years before caused such tubes or trumpets to be made, in order to strengthen the voice of a weak bass-singer; but he himself acknowledges that he never had an idea of speaking with them at a distance242.

      This instrument was soon made for sale at Nuremberg in Germany, particularly by that well-known artist Grundler, mentioned by Becher, who imagined that two persons, by means of a speaking-trumpet and an ear-trumpet, could converse together at a great distance, without any one in the neighbourhood, or in the intermediate space, hearing what they said.

Of those who employed their ingenuity in improving this instrument I shall mention the following. Cassegrain, known on account of his optical instruments, published some hints for that purpose in 1672243; as did Sturm244, Conyers245, Hase and others afterwards. The last who investigated the theory of the speaking-trumpet was Lambert246; according to whose ideas the figure of a shortened cone, if not the best, is at least as good as any other that might be employed.

      [It would appear, however, from the experiments of Hassenfratz (Journ. de Phys., t. xxvi.) that neither the shape of the instrument nor the material of which it is composed is of much consequence. He ascertained the power of the trumpet by fixing a small watch in the mouth-piece, and observing the distance at which the beats ceased to be audible, and thus found that the effects were precisely the same with a trumpet of tinned iron, whether used in its naked form, or tightly bound round with linen to prevent vibration, or when lined with woollen cloth whereby reflexion was entirely prevented; he also found that the range of a cylindrical trumpet was as great as that of a conical one.

Leslie supposes the effect of the trumpet to be owing to the more condensed and vigorous impulsion given to the air from its lateral flow being checked. He observes, “that the tube, by its length and narrowness, detains the efflux of air, and has the same effect as if it diminished the volubility of that fluid, or increased its density. The organs of articulation strike with concentrated force, and the pulses, so vigorously thus excited, are, from the reflected form of the aperture, finally enabled to escape and to spread themselves along the atmosphere247.”]

      FOOTNOTES

224 Goguet. i. p. 326.

225 Plin. lib. xvi. c. 38, p. 32.

226 Septalii Comm. in Aristotelis Problem. Lugd. 1632, fol. p. 206. There is also a passage to the same purpose in Seneca, Epist. 108.

227 See Anciennes Relations des Indes et de la Chine, de deux voyageurs Mahometans, qui y allèrent dans le neuvième siècle. Par Renaudot. Paris, 1718, 8vo, p. 25.

228 Ars magna lucis et umbræ. Amst. 1671, fol. p. 102. Kircher repeats this account with some new circumstances in his Phonurgia, p. 132.

229 Morhofii Diss. de vitro per vocis sonum rupto, in Dissertationibus Academicis. Hamburgi 1669, 4to, p. 381.

230 Morhof quotes the following passage:—“With this brazen horn, constructed with wonderful art, Alexander the Great called together his army at the distance of sixty miles. On account of its inestimable workmanship and monstrous size, it was under the management of sixty men. Many kinds of sonorous metals were combined in the composition of it.”

231 “Among many things which the celebrated D’Alance caused to be made for this purpose, the trumpet ascribed to Alexander, and with which he called together his army, ought not to be omitted. As the figure of it was represented in an old manuscript in the Vatican library, and had been described by Bettini, that learned man was desirous of trying whether it could be proved by experience, and the attempt succeeded; for that kind of trumpet, if it does not excel, seems undoubtedly to equal the other instruments constructed for that end.”

232 Bettini Apiaria univ. Philosophiæ Mathemat. СКАЧАТЬ