Page:The Kinematics of Machinery.djvu/621

 NOTES. 599

26 (P. 206.) See Rau, Drilling in Stone without Metal, Smithsonian Report, 1868. In the cause of archasological science Rau has made the tre- mendous sacrifice of completing such a boring with his own hands. With a wooden borer such as we have described he pierced a hand plate of Diorite, 45 mm. thick, by making two hollows on opposite sides and meeting in the centre. He succeeded only after two years' (more or less intermittent) work. The form of the hole made is exactly that of the holes in numerous rude axes found in various places in Europe.

In the Ethnographic department of the Berlin Museum there are several excellent specimens of American work in rock crystal, among others a specially characteristic carved horse's head of something like 70 mm. long.

Mr. A. R. Wallace, in his Narrative of Travels on the Amazon and the Rio Negro (p. 278), says : " I now saw several of the Indians with their most peculiar and valued ornament a cylindrical, opaque, white stone, looking like marble, but which is really quartz imperfectly crystallized. These stones are from four to eight inches long, and about an inch in diameter. They are ground round, and flat at the ends, a work of great labour, and are each pierced with a hole at one end. through which a string is inserted, to suspend it round the neck. It appears almost incredible that they should make this hole in so hard^a substance without any iron instrument for the purpose. What they are said to use is the pointed flexible leaf shoot of the large wild plan- tain, triturating with fine sand and a little water ; and I have no doubt it is, as it is said to be, a labour of years. Yet it must take a much longer time to pierce that which the Tushuaua wears as the symbol of his authority, for it is gene- rally of the largest size, and is worn transversely across the breast, for which purpose a hole is bored lengthways, from one end to the other, an operation which I was informed sometimes occupies two lives. The stones themselves are procured from a great distance up the river, probably from near its sources at the base of the Andes ; they are, therefore, highly valued, and it is seldom the owner can be induced to part with them, the chiefs scarcely ever."

26 (P. 208.) This subject is most fully treated by Girizroth, Wagen und FaTirwerlce der Griechen, Rdmer und anderer alter Vdlker, Munich, 1817 ; also W T eiss in several places. The four-wheeled vehicle was also in use, especially for carrying heavy loads. It had fixed axles, and was therefore much less easily guided than the two-wheeled one. In India there still exist, in the use of the natives, four-wheeled vehicles with a kind of moveable fore-carriage, an arrangement which must therefore be considered somewhat ancient. We know that the war- chariots of Porus were drawn into the immediate neigh- bourhood of the battle-field by draught oxen and not by horses. This may have occurred by no means unfrequently. It may well have happened that two of the empty chariots were then sometimes fastened together, the pole of the one to the frame of the other, and in this way a vehicle would be formed which had separate fore and hind carriages. The great ease with which such a compound vehicle could be guided must have struck its possessors, and may have led to the deliberate use of the revolving fore-carriage in regular vehicles.

27 (P. 208.) Wooden war-chariots would be burnt by the conqueror for lack of horses to carry them away, iron vehicles he would render useless by

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