After the fifth century there is no evidence as to the form of the halteres until Roman times. On Roman copies of athletic statues a new cylindrical type of halter is represented, and the same appears on mosaics and wall paintings.[546] It is merely a cylinder slightly narrower at the centre than at the ends, like a dice-box, and though very useful for dumb-bell exercises, can hardly have been as handy for jumping as the earlier types. We do not know when this type came in. The British Museum possesses a curious example of it, found at Camirus in Rhodes (Fig. 61). It is made of limestone, 7-1/2 inches long, and carefully grooved, so as to afford grips for the thumb and each of the fingers. References in late authors indicate that the halteres were usually not of stone, but of lead. Philostratus distinguishes two kinds of halteres: “the long,” which “exercise shoulders and hands”; the spherical, which “also exercise the fingers.”[547] It is clear that these cannot correspond to the two types which we found prevalent in the fifth century. For Pausanias regards one at least of these types as “old-fashioned,” and Philostratus is speaking of the halteres in use in his own day. Though he describes the halteres as an “invention of the pentathlon, and invented, as its name denotes, for the jump,” his ideas of their use for this purpose are of the vaguest,[548] and he regards them principally as a means of training, employed, he says, by all athletes alike, “whether heavy or light.” It seems, therefore, that his “long halteres” are those used by the heavy athletes, the boxer or the wrestler, while the spherical ones are those used by light athletes, the runner or the spear-thrower. The former may be identified with the cylindrical halteres; the latter are perhaps little more than balls of wood or lead, such as are recommended by a medical writer in the early fifth century A.D., for the use of those suffering from gout in their hands.[549] The manner of using the halteres is clearly shown on the vases. The principle is the same as that of a standing jump, the utilization of the swing of the arms to assist the spring of the legs. The jumper swings the halteres forwards and upwards till they are level with, or higher than, his head, and then swings them vigorously downwards, at the same time bending his body till his hands are just below his knees. The actual jump takes place on the return swing. As the hands swing to the front, and the centre of gravity is shifted forward, the knees, which have been bent on the back swing, are vigorously straightened, and the swing of the halteres combines with the push of the legs to propel the body forwards. In the case of a standing jump the preliminary swing may be repeated two or three times. [Illustration: Fig. 63. R.-f. pelike, in British Museum, E. 427.]