TRANSPORT MACHINES FOR SOLID BODIES.
Prroriiiuc Aicans of Transport: Thc first recourse of man for conveyance was his own back and limbs, and in sonic countries this method is still employed. The dog, the horse, the ox, the camel, the dromedary, cud the elephant have all been subjected to man's control for purposes of burden or of draught. The first mechanical means of trans port was doubtless the sled. It was employed by the Egyptians in the transfer of large masses of stone. In one of their sculptures is repre sented.a colossal statue on a sled drawn by one hundred and seventy two men in four rows, each row consisting of forty-three men. On the pedestal at the front of the sled stands a man with a vase, from -which lie pours a liquid, probably oil, for the purpose of lubricating the ways over which the sled moves. Standing on the knee of the statue is a man who appears to be clapping his hands as a signal for a concerted pull. Relays of drawers walk behind the sled, and following these are men car rying vases containing oil, or perhaps water, and other men with imple ments for some purpose, while supervisors or task-masters bring up the rear. The ropes for drawing the sled are all attached to its front. At Koyunjik a bas-relief shows that the sled was also adopted by the ancient Assyrians for removing the colossal figures from the quarry where they were hewn to the place they were intended to occupy.
Clesifihon' s Transport Machine.—Ctesiphon, when he wanted to con vey the shafts of the columns from the quarry to the temple of Diana at Ephesus, being unwilling to trust to carriages on account of the weight of the shafts, or to hazard the sinking of the wheels on account of the softness of the fields in the way, employed the ingenious contrivance exhibited in Figure 1, a (fil. ioS). It consisted of four pieces of timber (A, B, C, D), two (A, D) interposed transversely on two (B, C), equal to the length of the shaft of the column. At the ends A, D of the shafts he inserted dovetailed iron gudgeons (chodaces), which were secured with lead and fixed bearings (armlik) in the timbers for the gudgeons to revolve freely. The shaft, which revolved as does an agricultural roller,
was drawn by oxen by means of ropes attached to the poles F. Figure i, b, shows the vehicle for transporting an architrave.
Vehicles: origin of two-wheeled vehicles is attributed to Erechtheus (iztoo B. C.), but they are known to have been in use as early as zoo() B. C. The first forms of wheeled vehicles were doubtless carts and chariots. Carts drawn by oxen were used by the Scythians in the time of Herodotus (45o B. C.); the body of the cart was either permanent or detach able; if detachable, it constituted a felt-covered tent-frame, which could readily be placed on or removed from the running-gear. The first wheels of vehicles were narrow sections cut from the trunk of a tree and immov ably attached to the axle in the manner of the modern railway ear-wheels. The Chilian cart of to-day is a primitive vehicle, whose wheels are discs sawn or chopped from a log and bored for the axle, to which a tongue or pole is secured; there is thus formed the frame of the bed, which is some what like a city dray. The modern dnmping-cart for the removal of materials from excavations and for other purposes has the bed hinged to the axle, and is so contrived as to tilt and discharge the load when desired. For removing the earth excavated in constructing the founda tions of his numerous bridges, the French engineer Perronet employed coupled carts running on rails. Each cart had a bed capable of holding a cubic yard of earth, and was so suspended from the axle that a part of the contents was below the axle and nearly balanced the load, so that the earth was easily dumped. In the rear of the forward cart-frame was a shackle by which the second cart was attached to the one in front; each cart, therefore, could be separately loaded and drawn into the regular track, along which the coupled carts were drawn by a horse.