In this yard can be seen portable riveters suspended over a vessel’s deck between 40 and 50 feet above ground, capable of reaching and clenching rivets in stringers at a distance of 4 feet 6 inches from edge of plate. The power brought into play in closing some of these rivets is very great—from 20 to 30 tons—and yet this is conveyed by a small tube of only half-inch outside diameter in some cases through a distance of many hundred feet. The portable riveter here indicated is suspended on a light and handy carriage, which can travel the upper deck from stem to stern, being made purposely low so as to clear poop and bridge deck beams if such should be fitted. With this machine Messrs M‘Millan have closed from 400 to 450 rivets per day of nine hours in stringers 3 feet 6 inches wide. They have also effected some very heavy work in attaching the sheer strake to the gunwale bar, the rate of progress being correspondingly satisfactory. The same features in the _Alaska_, built by Messrs John Elder & Co., were similarly operated upon by another of Mr Tweddell’s riveters, whose complete system has been adopted in this large establishment also. By an elongation of the suspending arm Messrs M‘Millan hope to execute, besides the stringers, most of the deck work, such as ties, diagonals, hatch coamings, &c., in one traverse of the carriage. Moreover, a second carriage with riveter may be doing simultaneously the same work on the other side of the vessel. Indeed, it only requires a further development of such work to make the riveting of complete iron decks practicable, and—with the rate of wages, for hand riveted work, usually prevailing—profitable also. [Illustration: FIG. 22. TWEDDELL PORTABLE FRAME AND BEAM RIVETER.]