square stone pierced in the centre. A trap-door was anciently fitted to this stone, as is seen by the holes for the hinges, made on two opposite sides.107
The tholos communicates "with the aqueduct through a doorway 6 feet high, formed by an Egyptian vault of advancing stones, between which is a single wedge-shaped stone.
The gallery runs on 17 feet to a second doorway, similar to the first. Through this first length the roof is similar to that of the doorways. From the second doorway the passage takes a bend, and runs for 15 feet 5 inches wdth the same structure of roof; the walls are ancient, but restored with mortar. From the distance of 15 feet 5 inches onwards for 48 feet, the gallery is built of smaller blocks, and with a regular arch. From this point to the end 28 feet, the roof is formed by a single horizontal stone.
The tholos communicates wath the open air about half-way up its height by a second gallery, roofed with single blocks, which probably served for ventilation. This fountain seems to be the one mentioned by Theocritus, which, according to a legend, was discovered by Chalcon, king of Cos.108 The tholos reminded me of the Tullianum near the Capitol at Rome,109 and from the style of the masonry is probably of high antiquity.
I arrived in this island just in time to lay hands on an Ionian thief, immediately after he had been caught in a shop, with a false key in one hand and a bundle of goods in the other. Cos being within my consular district, I exercised summary jurisdic-
