The large spars were first cut down with adzes to the square, from the natural tree shape. The required taper to the yardarm was then marked off, and the square shape reduced to an octagonal for about the middle quarter length. Outside this length the spar was then shaped to a tapering round, the taper having a slight curve. The smallest spars might be left round in the centre section if the natural tree happened to be the right size. The eight-sided middle portion of the larger yards could also have the corners taken off again for sixteen sides, except that the after side flat was left large ifit had to take a wooden yoke. No doubt, in some instances the yard was rounded off over the middle portion to avoid special smithwork on the iron bands, but it was more usual to leave eight or sixteen sides.

  Iron yards for the lower topsail and possibly upper topsail yards were round, tapered, riveted tubes with open ends into which wooden plug yardarms were fitted.

  The outer stuns ail boom iron in its most common arrangement had two long straps bolted through the yardarm with the hoop set upwards and forwards at about 45°. There were some exceptions to this whereby the stunsail booms were slung below the yard and slightly aft of its centre to clear the chain sheets which ran below the yard. The Cutty Sark, Spindrift, Lord of the Isles, Glenaros, Fiery Cross of 1860, and Great Republic were rigged in this manner. The outer boom iron could also be detachable with its bent arm having a square prong which fitted into a square hole in the end of the yard, or else have a square hoop on the end of the iron to fit over a square iron on the yardarm tip with a locking pin.

  The jackstay bar to which the sail was attached was, on most of the clippers, an iron rod which went through a series of eyebolts either spiked into a wooden yard or riveted onto an iron one. There was a separate rod for each side, placed slightly forward of the central axis and held in place by forelock pins through the rods at each of their ends. Prior to this, earlier in the century, jackstays had been made either of wooden battens with a series of long apertures on the underside between the bolts or nails, or else a hem p or wire rope on each side leading through eyebolts and tightened in the centre by a connecting lanyard.

  The fitting below the centre of the lower yards to lead the topsail chain sheets down to the deck was, during the 1860s, in the form of two iron sheaves each with a separate pin, with cheek plates and straps, called a bullock block (43). Instead of this single fitting two separate iron blocks, each attached to its own iron yard band, could be fitted, being an older arrangement from the times when sheets were ofhemp instead of chain.

  For the yards which were not fixed in one position by a truss or crane -see the mastheads drawing (41)-a chain tye was attached to the central  band or to an iron span, depending on its size.