Though the rails surrounding the topes at Sanchi are not, in themselves, so interesting as those at Buddh Gaya and Bharhut, still they are useful in exhibiting the various steps by which the modes of decorating rails were arrived at, and the torans or gateways of the great rail are quite unequalled by any other examples known to exist in India. The rail that surrounds the great tope may be described as a circular enclosure 140 ft. in diameter, but not quite regular, being elliptical on one side, to admit of the ramp or stairs leading to the berm or procession-path surrounding the monument. As will be seen from the annexed woodcut (No. 29), it consists of octagonal pillars 8 ft. in height, and spaced 2 ft. apart. These are joined together at the top by a rail 2 ft. 3 in. deep, held in its position by a tenon cut on the top of the pillars, as at Stonehenge; between the pillars are three intermediate rails, which are slipped into lens-shaped holes, on either side, the whole showing how essentially wooden the construction is. The pillars, for instance, could not have been put up first, and the rails added afterwards. They must have been inserted into the right or left hand posts, and supported while the next pillar was pushed laterally, so as to take their ends, and when the top rail was shut down the whole became mortised together as a piece of carpentry, but not as any stone-work was done, either before or afterwards. [Illustration: 30. Rail, No. 2 Tope, Sanchi. (From a Drawing by Colonel Maisey.)] The next stage in rail design is exemplified in that of No. 2 Tope, Sanchi (Woodcut No. 30); there circular discs are added in the centre of each pillar, and semicircular plates at top and bottom. In carpentry the circular ones would represent a great nail meant to keep the centre bar in its place; the half discs, top and bottom, metal plates to strengthen the junctions--and this it seems most probably may really have been the origin of these forms. [Illustration: 31. Representation of Rail. (From a Bas-relief at Amravati.)] If from this we attempt to follow the progress made in the ornamentation of these rails, it seems to have been arrived at by placing a circular disc in each of the intermediate rails, as shown in the woodcut (No. 31), copied from a representation of the outer face of the Amravati rail, carved upon it. In the actual rail the pillars are proportionally taller and the spaces somewhat wider, but in all other respects it is the same--it has the same zöophorus below, and the same conventional figures bearing a roll above, both which features are met with almost everywhere. [Illustration: 32. Rail in Gautamiputra Cave, Nassick.]