The emperor Rudolphus II., who reigned from 1576 to 1612, and who was fond of, and acquainted with, the mechanical arts, possessed two very curious odometers, which not only pointed out distances, but also marked them down on paper by the way. The description and use of one of these is given by De Boot[21], who was that prince’s librarian; and what he says has been copied by Kircher[22], and illustrated with a coarse figure. It is not improbable that the before-mentioned Schissler was the maker of this instrument, as we are informed by Stetten that he constructed a great many machines and automata for the emperor Rudolphus II. The other odometer, which was much more curious, appears to have been constructed by that emperor himself[23].
About the end of the 17th century, an artist in England, named Butterfield, invented an odometer which met with great approbation. In the first volume of the Philosophical Transactions there are two papers written by this ingenious man; but of his odometer I have not yet been able to find a description.
In the beginning of the last century, Adam Frederick Zurner, to whom we are indebted for good maps of the electorate of Saxony, invented also an odometer, or geometrical carriage, a description and figure of which, taken from Schramm’s Saxonia Monumentis Viarum illustrata, is given by Nicolai. This instrument is not now to be found in the Dresden collection.
In Bion’s Treatise on the construction of mathematical instruments, improved by Doppelmayer, there is a description of a pedometer, and the author praises a new invention by one Sauveur.
In the year 1724 Meynier laid before the Royal Academy of Sciences at Paris an odometer, a short account of which, without a figure, is given in the history of the Academy for that year. This machine was afterwards improved by Outhier; and a description of the improvements, but without any figure, is to be found in the history of the Academy for 1742. A full description, together with a figure, may however be seen in a work, entitled Machines et Inventions approuvées par l’Académie, t. vii.
Perhaps the most perfect machine of this kind was that made at Berlin by an artist named Hohlfeld, a short account of which may be found in the ninth volume of the Hamburg 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[24]. 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 the celebrated Sulzer, at whose desire he undertook 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 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 the 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 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 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.