In the same collection is an odometer which Augustus, elector of Saxony, who reigned between the years 1553 and 1586, employed in measuring his territories. This instrument is mentioned by Beutel[19], without naming the inventor; but I think it very probable that it was made by Martin Feyhel, who was born at Naumburg, and resided at Augsburg; as Von Stetten[20] relates, in his History of the Arts at Augsburg, that Feyhel made a way-measurer (probably odometer) for the elector of Saxony, and that he himself called it a new instrument never before heard of. This artist was an intimate friend of the celebrated Christopher Schissler, also of Augsburg, who in 1579 constructed a quadrant, still to be found at Oxford; and in 1606 an armillary sphere, still preserved at Augsburg. 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.