very light, is practically of no weight for a horse. Coming down-hill with a load a rigid vehicle has to be employed in any case, and so the slide-car is equally efficient, the chief drawback being that it can carry so little, but this is not of much account in small holdings. The slide-car has, further, the great recommendation of being made easily and cheaply without requiring the services of a skilled carpenter or wheelwright. It is also as easily repaired, and all the materials are ready to hand.

It is also interesting to note that these very primitive carts can be constructed entirely of wood and thongs, or ropes, and there is no necessity for any metal to be employed.

We now come to a gap in the evidence of the evolutionary history of the cart that is not easy to fill. What was the precursor of the wheel? There can be little doubt that the wheel was derived by slow modifications of an antecedent object, and there is a strong presumption that this "missing link" was a roller, but there does not appear to be any positive evidence to render this view absolutely certain.

The mechanical principle of the roller was known to remote antiquity, and it is generally accepted that the great stones of megalithic monuments, such as menhirs, cromlechs, and the like, were transported in this manner, as we know were the great statues of Assyria and Egypt.

It is not presupposing too much to surmise that a cylindrical tree-trunk might be placed beneath the shafts of a slide-car, or of a sledge, in order to reduce the friction. A constructional problem arises from the difficulty of keeping it in position. This could be overcome in the former by placing a short roller between the shafts and fixing a pin in the centre of each end of the roller, which could then revolve in a notch in the shafts, as in the accompanying diagram, or between two pegs, as in the Portugese cart, Fig. 31.

We must imagine a further development, which is also missing from Ireland, in the reduction of the central portion. This would become the practice as soon as man discovered that efficiency was increased by reducing the long frictional surface, and that the weight was lessened.

Herr Stephan, the late enlightened PostmasterGeneral of the German Empire, to whom we owe the introduction of the post-card, described, according to Poesche,* a very primitive cart that he saw in Portugal. A log is cut from the trunk of a large tree, the central portion is hacked away so as to leave a solid disc at each end joined by an axle. Poesche also mentions an ancient Egyptian battle scene, in which a large Aryan woman is depicted carrying off a wounded brother, husband, or son, on a waggon with similar wheels drawn by oxen.

* T. POESCHE, Die Arier, 1878, p. 98.

This explanation of the origin of wheels has been adopted by various writers* who have, however, regarded the sledge as the parent of the cart, as it was on sledges that the colossal statues of Egypt and the winged bulls of Assyria were rolled.

Dr. E. Hahn, however, in his learned and sugges

A

B

FIG. 23.

Diagrams illustrating a probable evolution of wheels from a roller.

tive essay, Demeter und Baubo, argues against this view. He thinks that in this case wheeled vehicles would have arisen wherever rollers have been employed; but it is not so, the waggon arose only in the district from which agriculture originally spread. He

* REULEAUX, Theoretische Kinematik, Braunschweig, 1875, p. 204; Kinematics of Machinery.

E. B. TYLOR, "On the Origin of the Plough and Wheel-carriage," Journ. Anth. Inst., x., 1880, p. 74.

believes that the waggon was primitively a holy implement consecrated to the great goddess of agriculture and fertility, and that it only subsequently became a secular farm implement.

Dr. Hahn* definitely states as his belief that the waggon has arisen because the wheel existed. The wheel in its most simple form is only a disc pierced through the centre. Such discs of stone, clay, &c., occurred in the same culture district as that in which agriculture arose, and was at the same time an implement and a religious object. This is the spinning whorl, and the sacred symbols, such as the svastika, on numerous whorls from Hissarlik, suggest that they were often used as votive offerings. As spinning was an occupation of the women, these whorls were probably dedicated to a female divinity, presumably to the goddess of Nature and generation.

It is only necessary to stick two or four of these whorls on one or two pieces of stick, and to fasten something over the axis, and a waggon would result. That these whorls are not large explains also the small size of many holy waggons. Later, following this model, large waggons were made, and these holy waggons were drawn by the sacred animal of the great goddess, the ox, and conveyed the image of the goddess.

* E. HAHN, Demeter und Baubo, Versuch einer Theorie der Entste hung unsres Ackerbaus, 1896, Lübeck.

There is no need to follow Dr. Hahn in his disquisition on the curious wheeled objects of the Bronze Age, which were probably votive offerings, or at all events were religious symbols. His idea is that the small objects were symbols of the large real waggon in which rode the god or goddess, or the image of the deity.

Most students of ceremonial institutions will probably demur to Hahn's position. In the first place, there is no reason to believe that agriculture was discovered only in some area of Eurasia, and that the art thence spread over the greater part of the habitable world. Then the evolution of spindle whorls into cart wheels scarcely appears probable. It seems more in consonance with what we know of the history of sacred institutions and implements, that the waggon had an industrial origin, and it may well be that it arose in close connection with agriculture; the operations of agriculture have always been closely connected with religion, and there is no reason to deny that the agricultural cart at its inception may have been associated with the cult of agriculture. The small size of the votive offerings or wheeled symbols is no matter for surprise. On the whole, then, we may accept the older view of the origin of wheels as being the more probable alternative.

Dr. Hahn points out that he is dealing solely with the four-wheeled ox-waggon which was used for