Crossing the masts are the yards. On the mainmast we have, beginning below, main-yard, lower maintopsail-yard, upper maintopsail-yard, lower maintopgallantsail-yard, upper maintopgallantsail-yard, main royal-yard and skysail-yard; on the foremast we have the fore-yard, then the topsail-yards, topgallantsail-yards and royal; and on the mizzenmast we have a similar series of yards, beginning with the mizzen or crossjack.
Up to the close of the last century, in very old ships, there was no sail hung on this lower yard of the mizzenmast, it having been introduced only for setting the mizzen topsail; and instead of the gaff spanker we now have there was a huge lateen sail which extended some distance forward of the mast and worked under this yard.
This lateen was the crossjack. When the gaff came in, the projecting corner of the lateen disappeared so as to make room for the sail hanging from this lower yard, and the yard took the name of the old lateen boom.
As representing, then, the after half of this huge boom, we have the modern gaff, set at the same angle as the boom used to be; and at the foot of the sail hung on this gaff, now called a spencer or spanker, from the original inventor, we have the spanker boom, the same sort of thing as we should call the mainboom were the vessel a fore-and-aft yacht.
Each mast is held in its place by stays and backstays. The stays reach from the mastheads to the centre line of the ship forward; and the backstays come down to the sides of the ship, just behind the masts.
The stays and backstays are named from the mast-head from which they descend. Thus the forestay comes from the foremast-head to the bows; the foretopmast-stay from the foretopmast-head to the bowsprit-head; the foretopgallant-stay from the foretopgallant-rigging to the jibboom-head; and the foreroyal-stay from the top of the royal mast to the end of the flying-jibboom.
From the bowsprit-head to the vessel's cutwater runs the bobstay, generally of chain, which takes the pull of the foretopmast-stay; and from the bowsprit-head there hangs the spar known as the dolphin-striker, to give the purchase for continuing the pull of the foretopgallant and foreroyal stays round to the cutwater; so that really all the staying starts from the hull, as does the backstay-staying.
Round the lower mastheads are platforms called tops; and round the topmast-heads are skeleton platforms called crosstrees. These platforms are required not only to take the lower ends of the topmast and topgallant rigging, but also to enable the crew to strike and get up the masts and yards and work the sails. The crosstrees are fitted with outriggers pointing outward aft to enable the topgallant-backstays to give a better support to the topgallantmast than they otherwise would do.
Besides stays and backstays, the masts have "shrouds" to strengthen them. The topgallant shrouds come from the head of the topgallant-rigging to the crosstrees, the topmast shrouds come from the hounds just under the crosstrees to the top, and the main, fore or mizzen shrouds, as the case may be, come from just under the tops to the vessel's side.
To take the pull off the tops, the shrouds are continued round to the mast as "futtock" shrouds, on the same principle as the foretopmast-stay finds its continuation in the bobstay.