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MACHINE FOR NOTING DOWN
As I have occasionally mentioned in the preceding article, a machine for noting down any piece of music played on a harpsichord or other musical instrument, I shall here add a short history of the invention of it, as far as I know; and with the greater pleasure, as another nation has laid claim to it, though it belongs to my countrymen.
It appears incontestable, that a proposal for inventing such a machine was first made known by an Englishman. In the month of March, 1747, John Freke transmitted to the Royal Society a paper written by a clergyman of the name of Creed, which was printed in the Philosophical Transactions under the following title: "A De"monstration of the possibility of making a ma"chine that shall write extempore voluntaries, or "other pieces of music, as fast as any master shall "be able to play them upon an organ, harp"sichord, &c; and that in a character more na"tural and intelligible, and more expressive of "all the varieties those instruments are capable "of exhibiting, than the character now in use. The author of this paper, however, points out the
* See Philos. Transact. vol. xliv. p. ii. no. 483. p. 446. Also Martin's Abridgement, vol. x. p. 226.
possibility only of making such a machine, without giving directions how to construct it.
In the year 1745, John Frederic Unger, then land-bailiff and burgomaster of Einbec, and who is known by several learned works, fell upon the same invention without the smallest knowledge of the idea published in England. This invention, however, owing to the variety of his occupations, he did not make known till the year 1752, when he transmitted a short account of it, accompanied with figures, to the Academy of Sciences at Berlin. The Academy highly approved of it, and it was soon celebrated in several gazettes, but a description of it was never printed.
A few days after Euler had read this paper of Mr. Unger's before the Academy, Mr. Sulzer informed Hohlfeld of the invention, and advised him to exert his ingenuity in constructing such a machine. In two weeks, this untaught mechanic, without having read Mr. Unger's paper, and even without inspecting the figures, completed the machine, which Mr. Unger himself had not been able to execute through want of an artist capable of following his ideas.
Unger's own description of his invention was printed, with copper plates, at Brunswick, in the year 1774, together with the correspondence between him and Euler, and other documents. A description of Hohlfeld's machine illustrated with figures, was published after his death, by Mr.
Sulzer, in the new Memoirs of the Academy of Berlin,* under the title of "Description of a ma"chine for noting down pieces of music as fast as
they are played upon the harpsichord." Sulzer there remarks, that Hohlfeld had not followed the plan sketched out by Mr. Unger, and that the two machines differed in this-that Unger's formed one piece with the harpsichord, while that of Hohlfeld could be applied to any harpsichord
When Dr. Burney visited Berlin, he was made acquainted with Hohlfeld's machine by Mr. Marpurg; and has been so ungenerous, or rather unjust, as to say in his Musical Travels, that it is an English invention, and that it had been before fully described in the Philosophical Transactions. This falsehood Mr. Unger has sufficiently refuted. Without repeating his proofs, I shall here content myself with quoting his own words, in the following passage: "How can Burney wish to deprive
our ingenious Hohlfeld of the honour of being "the sole author of that invention, and to make
an Englishman share it with him, because our "German happened to execute successfully what "his countryman Creed only suggested? Such
an attempt is as unjust in its consequences, as it "is dishonourable to the English nation and the English artists. When we reflect on the high
See Nouveaux Mémoires de l'Académie à Berlin, année 1771,
"estimation in which music is held in England; "the liberality of the English nobility, and their "readiness to spare no expenses in bringing for"ward any useful invention, a property peculiar
to the English; it affords just matter of surprise, "that the English artists should have suffered "themselves to be anticipated by a German journeyman lace-maker. To our Hohlfeld, "therefore, will incontestably remain the lasting "honour of having executed a German invention; " and the Germans may contentedly wait to see "whether Burney will find an English mechanic "capable of constructing this machine, from the "information given by his countryman Creed."
REFINING GOLD AND SILVER ORE BY QUICKSILVER.
It is well known that quicksilver unites very readily with almost all metals, and when added in a considerable quantity forms with them a paste which can be kneaded, and which is called amalgam. On the other hand, as it does not suffer itself to unite with earth, being a metallic substance, it furnishes an excellent medium for separating gold and silver from the earth and stones in which they are found. The amalgam is squeezed through a
piece of leather, in which these precious metals remain with a certain portion of the quicksilver; and the former are freed from the latter by means of fire, which causes the semi-metal to evaporate. This amalgam made with gold serves also for gilding metals, if it be rubbed over them, and afterwards heated till the quicksilver be dispersed by evaporation.
The first use of quicksilver is commonly reckoned a Spanish invention, discovered about the middle of the sixteenth century; but it appears from Pliny, that the ancients were acquainted with amalgam, and its use, not only for separating gold and silver from earthy particles, but also for gilding. Vitruvius describes the manner of recovering gold from cloth in which it has been interwoven. The cloth, he says, is to be put into an earthen vessel, and placed over the fire, in order that it may be burnt. The ashes are to be thrown into water, and quicksilver added to them. The latter attracts the particles of the gold, and makes them unite with it. The water is then to be poured off, and the residue put into a piece of cloth; which being squeezed with the hands, the quicksilver, on account of its fluidity, oozes through the pores, and the gold is
* Argentum vivum exest ac perrumpit vasa, permanans tabe dira -Optime purgat aurum, cæteras ejus sordes exspuens crebro jactatu fictilibus in vasis.—Sed ut ipsum ab auro discedat, in pelles subactas effunditur, per quas sudoris vice defluens, purum relinquit aurum. Ergo et cum æra inaurantur, sublitum bracteis pertinacissime retinet. Vol. ii. p. 622. edit. Hard. or book xxxiii. chap. 6.