The lead covering of old roofs should be jealously maintained--its loss is irreparable. If repair becomes absolutely necessary for the protection of the building, such lead should be recast, it should never be replaced by milled lead. The old metal is easily recast on the ground, and this is now frequently done, but not frequently enough. It was cast on a wood table with a projecting margin or curb all round; on this slid up and down a cross piece notched down to give the proper gauge to the lead which it levelled. Where lead was applied to the vertical or steep planes of dormers or spires the interlocking of the sheets in herring-bone was a practical as well as an artistic expedient. Where nails had to be driven through exposed lead, in repairs or otherwise, flaps like little shields were laid over them soldered on the top edge. Lead, where used to incase wood tracery, as in the open work of spires or dormers, was secured by means of laps and rolls without solder so that it was free to expand and contract. The modern plumber is much too apt to employ soldered joints even in structural work. Small openings were made like little dormers, for ventilation of the roof timbers, by dressing a stout piece of lead up into a triangle or half circle in front dying back on the roof with the back turned up under the tiles or slates. Sometimes cast ornaments were applied to a slated roof; the disc with undulating rays on the slated apex of the north-west tower at Rouen is an instance. § VII. OF LEAD COFFINS. In the later classical period lead was much used for coffins; several of very fine workmanship have been discovered in Syria, some of these, very delicately ornamented are figured by Perrot, and Chipiez.[9] In the Louvre there is a finely decorated example of the Roman period, and large numbers of Roman lead coffins have been found both in England and in France. There is a very beautifully decorated early Christian coffin in the museum at Cannes, this has a border of vine and birds with monograms of Christ--ΧΡ. ΙΧΘΥΣ.[10] Fig. 15 shows portions of ornamentation from a remarkable series of coffins now in the museum of Constantinople. There are some eight or ten of these and all decorated in the most elaborate way with tendrils and medallions beautifully modelled in very slight relief. None of the symbols are definitely Christian, but they evidently belong to the same school as the last named. The neighbourhood of Beyrout and the ancient Sidon was the site of the discovery of most of these coffins of early Christian date. [9] _History of Art_, “Phœnicia.” [10] Illustrated by Reber. [Illustration: FIG. 15.--Ornaments from early Christian Coffins, Constantinople.]