prevent the carriage running back. The outer ways are of the section of an ordinary I girder, with a rail cast on the top. The distance apart from centre to centre of outer ways is 30 ft., the ways being kept to their proper gauge by means of cast iron stays placed at intervals of 18 ft., and bolted to the ways. The ways are cast in lengths of 9 ft., the faces of meeting, or ends, being faced or planed so that a correct joint and continuous bearing surface is produced, each length being bolted to the other by bolts passing through the end flanges. Above high-water mark the ways are bolted to sleepers of hinau or totara 12 in. X 10 in., the sleepers being 3 ft. apart from centre to centre, the centre sleepers being 6 ft. in length, and the outer ones 3 ft. The greater portion of the surface consists of rock, which was excavated to the required depth to admit the sleepers and ways, which, after being accurately levelled and graded, were grouted in with Portland cement, and the ground levelled up to the bottom of the rail with rubble. In one or two places the ground was too soft to carry the ways with safety in this manner, and in these cases piles were driven to depths varying from 5 ft. to 15 ft., to which the sleepers were secured. Below high-water mark the ways or rails are bolted to cross sleepers of totara, 33 ft. in length and 12 in. x 10 in., at intervals of 3 ft. centres; four piles being driven under each sleeper, until a depth of 14 ft. of water at high tide was reached. This depth being sufficient to allow 8 ft. of water over the carriage, it was not considered necessary to extend the piles beyond this depth, as a large vessel would weigh very little on the carriage when drawing this amount of water. Beyond this depth, four longitudinal timbers were laid under the sleepers, two being under the centre rail, and one under each of the outer rails. Where the contour of the bottom of the bay differed from the inclination or gradient of the ways, cast iron stanchions or columns are introduced between the sleepers and the ways. The whole of the timber is covered with concrete to protect it from the ravages of the worm. It was contemplated when the slip was designed, that the site on which it was to be fixed would be sufficiently solid to carry the ways or columns without the intervention of sleepers. The cost of the material would have been considerably reduced had the exact nature of the bottom been known when the design was prepared. The actual weight per foot run of ways and stays, or distance pieces, is about 7 cwt., and to this has to be added the weight of the columns or stanchions, as well as the bolts and other fastenings. The total length of the ways laid down is 1,050 ft. The gradient, or inclination, is 1 in 23. At the end of the ways, a stop is fixed in the centre line to prevent the carriage from over-running the rails when a vessel is launched. The carriage or cradle is 250 ft. in length on the centre beams, and is made in two pieces; the principal length, which is 180 ft. long, being sufficient to accommodate the class of vessels now frequenting the port of