The Cross and Platform at Richborough

( 217 ) THE CROSS AND PLATFORM AT RICHBOROUGH BY WM. H. ELGAR. FOREMOST among the surprises of the late war must be placed the mystery port of Richborough, situated amid the lonely marshes surrounding the mouth of the Kentish Stour—the port from which thousands of tons of arms and ammunition, all unknown to the enemy, were ferried over to the Continent; and foremost among unsolved archaeological problems is the mysterious mass of concrete within the walls of Roman Richborough, upon which are the even more puzzling cruciform concrete foundations. After reading the various reports of investigations at the great concrete platform, and the several ideas as to the structure which it was designed to support, and after very carefully examining the massive remains, the following suggestions are put forward as likely to offer a solution of the mystery. The cross upon the platform, it will be remembered, has a long narrow arm running in a northerly direction, traversed by a wider and shorter one running east and west. The narrow arm is about 8 ft. 6 ins. wide and 86 feet long ; the other is 22 feet wide and 47 feet long. Enclosing the cross are the remains of a wall more than two feet thick, near which numerous architectural fragments of marble have been discovered. It is an indisputable fact that the several narrow streams, by which the Stour enters the ocean, were once united in a great navigable arm of the sea, a strait separating the Isle of Thanet from the mainland, and that the high ground upon which Richborough stands was an island. The old Roman Road connecting that port with Canterbury, can still be traced stretching away towards the city from the principal gateway near the centre of the western wall. 218 THE CROSS AND PLATEORM AT RICHBOROUGH. Richborough Island thus formed a breakwater against the tidal currents, and it is believed that the Roman galleys anchored in the channel behind the island, where future excavations may, it is hoped, establish the fact. Since the time of Leland, the writer of the "Itinerary", who toured our country when Henry VIII was reigning, the fort of Richborough has been the wonder and despair of the antiquary. Such a mass of concrete, over 30 feet deep, 126 feet from north to south and 81 feet from east to west, was strong enough to support an immense super-structure, and yet the only indication of any building upon it is the concrete cross, now no more than A\ feet high in any portion. True, its angles, formerly, were protected with squared tufa blocks, which disappeared within recent times, and, with them, the last evidences from which any hints could be expected towards the solution of the mystery. Several conjectures have been made as to the purpose of the platform, but none of them satisfactorily accounts for the existence of the cross. The long, thin arms, stretching north and south, have proved the stumbling blocks upon which many speculations have been wrecked. By making them the all-important problem, the crux, the present solution has been reached. A tall, thin structure, that might be erected upon such a foundation, could only contain narrow passages, not much more than three feet in width, so that any stairways would most likely have been situated in that portion of the building which stood upon the wider arms of the cross. Placing a stah in the western half of this arm, the eastern portion would be available for a series of chambers, also served by the same stahs. This, I submit, would be the only practical structure that could be raised upon such a foundation as the concrete cross. Polybius, the historian (B.O. 204-122), gives a description of a method of signalling in the Roman Army, a method which had been perfected by himself. Arranging the twentylour letters of the Greek alphabet in four groups of five and one of four, it became possible to signal each letter by THE CROSS AND PLATEORM AT RICHBOROUGH. 219 indicating to which set it belonged and its place in the set. Thus " delta " would be shown by 1 and 4, being the fourth letter in the first group. As to our structure erected upon the mystery cross, five galleries, one above the other in the narrow arm, have two windows in their eastern faces, forming two tiers of openings about 70 feet apart. Attendants stationed at these openings could exhibit torches by night or flags or other objects by day, as directed by officers occupying one or other of the rooms in the eastern part of the building on the wide arm. " Delta " then would be signalled by showing four lights in the one tier, and one light in the other. In short, such a structure is admirably adapted for signalling in the Roman manner, and, being on the coast, must have been intended for the use of ships at sea. It could also be used to transmit messages inland. Openings on the western face of the narrow arm would enable this to be done quite easily. Only one beacon light would be seen from a ship at sea until it had passed considerably to the north or south of the lighthouse ; and most likely these lights were so placed and at such a distance from the screen wall that the second light became visible when the vessel had proceeded far enough north or south to enable it to pass into the channel north or south of the island. Thus the mariners would turn to port or to starboard as the case might be, immediately the light became double, if making for the anchorage by night. Of necessity it follows that, if the tower were used as a lighthouse, fuel would be required for the beacon, and it would have to be stored in the vicinity, probably in the space between the tower and the enclosing wall, which may have been erected to hide it from view. The wall was given a monumental as well as a useful character by a surrounding colonnade, of which many fragments have been recovered. Portions of bronze figures also are among the relics, and for this reason it is suggested that they adorned the roof of the colonnade.