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burgh Magazine. A complete description I have not seen; but I learn from professor Bernoulli's Tour through Brandenburg, Pomerania, &c., that a model of it is preserved in the excellent collection of count de Podewils, at Gusow. * The inventor of it was a man of such rare talents, and rendered such benefit to the public, that the following anecdotes of his life may prove not unacceptable to many readers. It was written by professor Muller at Berlin, and transmitted to me by Dr. Bloch.

Hohlfeld was born of poor parents, at Hennerndorf, in the mountains of Saxony, in 1711. He learned the trade of lace-making at Dresden, and early discovered a turn for mechanics by constructing various kinds of clocks. From Dresden he removed to Berlin to follow his occupation. As he was an excellent workman, and invented several machines for shortening his labour, he found sufficient time to indulge his inclination for mechanics; and he made there, at the same time that he pursued his usual business, air-guns and clocks.

In the year 1748 he became acquainted with

* This machine was used by Sulzer during his tour. See his Journal, published at Leipsic 1780, 8vo. p. 3. It has been since improved by Schumacher, a clergyman at Elbing. Neueste Mannigfaltigkeiten, 1774, p. 1. The latest improvements are by Klindworth, Catel at Berlin, and by an anonymous clergyman in Schwabischen Magazin, 1777, p. 306. See Gottingisches Taschenbuch, 1778, p. 76, and Nicolai Reise in the Appendix, p. 18.

the celebrated Sulzer, at whose desire he under took the construction of a machine for noting down any piece of music when played on a harpsichord. A machine of this kind had been before invented by Mr. Von Unger; but Hohlfeld, from a very imperfect description, completed one without any other assistance than that of his own genius. Of this machine, now in possession of the Academy of sciences at Berlin, Sulzer gave a figure, from which it was afterwards constructed in England. This ingenious piece of mechanism was universally approved, though several things may be wanting to render it complete; but no one was so generous as to indemnify the artist for his expenses, or to reward him for his labour.

About the year 1756, the Prussian minister, count de Podewils, took him into his service, chiefly for the purpose of constructing water-works in his magnificent gardens at Gusow. There he invented his well-known thrashing-machine, and another for chopping straw more expeditiously. He also displayed his talent for invention, by constructing an apparatus, which, being fastened to a carriage, indicates the revolutions made by the wheels. Such machines had been made before, but his far exceeded every thing of the like kind. Having lost this machine by a fire, he invented another, still simpler, which was so contrived as to be buckled between the spokes of the wheel. This piece of mechanism was in the possession of

Sulzer, who used it on his tour, and found that it answered the intended purpose.

In the year 1765, when the present duke of Courland, then hereditary prince, resided at Berlin, he paid a visit to Hohlfeld, and endeavoured to prevail on him to go to Courland, by offering him a pension of 800 rix-dollars; but this ingenious man was so contented with his condition, and so attached to his friends, that he would not, merely for self-interest, quit Berlin. His refusal, however, obtained for him a pension of 150 dollars from the king.

Besides the before-mentioned machines, he constructed, occasionally, several useful models. Among these were a loom for weaving figured stuffs, so contrived that the weaver had no need of any thing to shoot through the woof;* a pedometer for putting in the pocket; a convenient and simple bed for a sick person, which was of such a nature that the patient, with the least effort, could at any time raise or lower the breast, and when necessary convert the bed into a stool; and a carriage so formed, that if the horses took fright, or ran away, the person in it could, by a single push, loosen the pole, and set them at liberty. The two last models have been lost.

Every machine that this singular man saw, he altered and improved in the simplest manner. All

*This model is preserved in the collection of the Academy.



his own instruments he made himself, and repaired them when damaged. But as he was fonder of inventing than of following the plans of others, he made them in such a manner that no one except himself could use them. Several of his improvements were, however, imitated by common workmen, though in a very clumsy manner. It is worthy of remark, that he never bestowed study upon any thing; but when he had once conceived an idea, he immediately executed it. He comprehended, in a moment, whatever was proposed; and, at the same time, saw how it was to be accomplished. He could, therefore, tell in an instant whether a thing was practicable; if he thought it was not, no persuasion or offer of money could induce him to attempt it. He never pursued chimæras, like those mechanics who have not had the benefit of education or instruction; and though this may be ascribed to the intercourse he had with great mathematicians and philosophers, there is every reason to believe, that he would have equally guarded against them, even if he had not enjoyed that advantage. The same quickness of apprehension which he manifested in mechanics he showed also in other things. His observations on most subjects were judicious, and peculiar to himself; so that it may be said, without exaggeration, that he was born with a philosophical mind.

With regard to his moral character, he was very different from those of the same class. Though

he still retained something of the manners of his former condition, his mild and civil deportment rendered his company and conversation agreeable. He possessed a good heart, and his life was sober and regular. Though he was every day welcome at the best tables, he stayed for the most part at home, through choice; went to market for his own provisions, which he cooked himself; and was as contented over his humble meal as Curius was over his turnips.

A little before his death, he had the pleasure of seeing a curious harpsichord he had made, and which was purchased by his Prussian majesty, placed in an elegant apartment in the new palace at Potsdam. As he had for some time neglected this instrument, the too great attention which he bestowed on putting it in order contributed not a little to bring on that disease which at last proved fatal to him. His clock having become deranged during his illness, he could not be prevented, notwithstanding the admonition of his friend and physician Dr. Stahls, from repairing it. Close application occasioned some obstructions which were not observed till too late; and, an inflammation taking place, he died, in 1771, at the house of count de Podewils, in the 60th year of his age.

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