If spencers or trysails (the small fore and aft sails with gaff, on the fore or main masts) were fitted on large hooped masts, the mast would be too large to conveniently take the gaff jaws or the hoops on the luff of the sail, so a much smaller mast was stepped close to the larger with its head let into a chock between the trestle trees and its foot stepped in a socket on deck or to a mast band with an eye or socket a foot or so above the deck. This small diameter mast took the gaff jaws and also the wooden hoops seized to the sail. If the mizzenmast was considered too large it also would have a try sail mast, which served the same purpose as the extra mast which distinguishes a small craft called a snow. A vertical iron rod jackstay bolted to the aft side of the mast with a gooseneck fitting on a band for a hooked iron on the end of the gaff, served the same purpose as the trysail mast and by mid-century seems to have been fairly common on wooden masts and was carried on in the same fashion for iron masts. The gaff of course was the non-lowering type, and the head of the trysail ran on hoops along it with an outhaul and inhaul, the body of the sail being brailed from blocks attached to the jackstay or mast.

  Iron masts were built intermittently from early in the century, especially for steamships, but it was in the 186os, with the composite clippers, when they became the general rule, at first for lower masts only and then for topmasts as well. The lower yards and bowsprit were also of iron, and the lower topsail yards, if large enough. The extra strength of iron masts coupled with the more rigid iron wire rigging encouraged a greater spread to the courses which was apparent in the later clippers.

  Iron masts, however, had their problems too, and many collapsed, chiefly due to localized bad riveting and insufficient internal stiffening. The restricted space inside the masts made it difficult for rivets to be held up efficiently while being hammered on the outside, and if a small man or boy could not do it, a long rod was used as a lever to hold up a heavy iron dolly like along mallet fitting against the rivet head, which was inserted from the inside.

  I recall an incident during the reconstruction of the Cutty Sark involving one of these dollies, with near-fatal results. One of the ship's masts, which had been a replacement after a dismasting, was found to be some feet too short, and in consequence I suggested adding the requisite length to the heel, thus avoiding altering the top and its cheek plates. This meant raising the mast by chain hoists inside the hold, seized around a heavy iron bar which passed through two holes burned out of the mast. The mast had a full-Iength vertical diaphragm plate as a stiffener, and a manhole was cut into the mast near the holes so that the diaphragm could be penetrated also. After the strain had been taken on the hoists, a shipwright put his head into the manhole to see if all was correct and as he withdrew it, a loud clatter was heard as a heavy iron dolly came hurtling downwards and bounced upwards again from the keel.