ON DRAUGHT. 545 



Egypt, was removed from one square, in which it stood, to another near the 

 Vatican, and there again erected in the spot where it now is. 



In dragging this through the streets of Rome, it was fixed in a strong frame 

 of wood, which rested upon a smaller frame, which were furnished each with a 

 pair of rollers, or spindles, of the form above referred to ; they were turned 

 by capstan bars : indeed they cannot be better described than by stating that 

 they resembled exactly the naves of a pair of cart-wheels (all the spokes being 

 removed), and fixed to a wooden axle. If a heavy waggon lay upon a pair of 

 these, we can conceive that by putting bars into the mortices of the naves, we 

 could force them round, and thus advance the waggon ; but the resistance would 

 evidently be greater than if either rollers or wheels were employed. 



All the difficulties incidental to the use of the roller appear to be surmounted, 

 and all objections met, by the contrivance of the wheel. 



The wheel being attached to the load, or to the carriage which contains it, 

 moves with it, is part of the machine, and consequently as we require only the 

 number of wheels immediately necessary for the support of the load, we can 

 afford to construct them of those dimensions and materials best suited to the 

 purpose. By increasing their diameter, we are enabled to surmount impediments 

 with much greater facility, as we have shown in the case of the roller; and although 

 there is a resistance arising from friction at the axle, which does not exist in the 

 roller, yet this may be so reduced, by increasing the diameter of the wheel, as to 

 form an inconsiderable part of the whole resistance, or draught of the carriage. 



Of the first introduction of the wheel we have no record whatever. The 

 principle appears to us so simple as to have been necessarily the result of pure 

 invention, almost of inspiration ; while, at the same time, it is so exceedingly 

 effective and perfect, as hardly to admit of improvement. 



The great antiquity of wheeled carriages or chariots precludes all hopes of 

 discovering their origin. About fifteen hundred years before the Christian era 

 they appear to have been in common use amongst the Egyptians in their warfare. 

 Pharaoh despatched six hundred chosen chariots in pursuit of the Israelites, 

 while the rest of the army followed with all the chariots of Egypt : here, 

 therefore, they were in general use, and serving as the cavalry of the present day. 

 Moreover the oldest records, which enter into any detail of their construction, 

 describe them as in a very forward and perfect state. 



At the siege of Troy, nearly three thousand years ago, they formed, according 

 to Homer, the cavalry of the Greeks and Trojans ; and every officer or hero of 

 good blood possessed, at least, a pair of horses and a charioteer. 



These chariots being built to run over broken ground, where no roads existed, 

 were made low and broad, and they were by no means badly contrived for 

 the purpose for which they were intended ; the wheels were constructed with 

 a nave and spokes, felloes and tires ; and the pole a, appears to have been 

 fixed on the axle-tree, 6, in the manner shown hi Jig. 26. The body of the 



Fig. 26. 



chariot was placed upon this frame. The team generally consisted, as we have 

 before stated, of a pair of horses, attached to the pole ; six and even a greater 

 number of horses were, however, frequently harnessed abreast, but in that case 



