Sail plans    

The era of the tea clippers saw important changes in the sail plans of ships. Early in the 19th century three-masted ships had each mast divided into three parts, the lo.wer mast, the topmast and the topgallant mast. The mizzenmast before this time set a spanker, which was a development of the old triangular lateen with the portion before the mast omitted, and was loose footed with no boom. A boom was later fitted, but the mizzen lower yard or crossjack (cro'jack) was used only to spread the topsail, carrying no sail itself. The French called it la vergue seche-the barren yard.
It was not until the mid 1830s that an American skipper decided to set a sail on this yard, a move received with a little derision at first by his British counterparts as it was considered to have little effect, but by the next decade most American packet ships were carrying this sail, and eventually the British.

  The topmasts carried only one sail, huge and difficult to handle, on the fore and main masts. It carried usually three rows of reef points, four on some of the largest American clippers. This single topsail had to be reefed or furled by men laying out on the yard, a task which could take up to half an hour.

  In 1841 an American, Captain Forbes, devised a means of dividing this sail horizontally into two parts. The dQubling of the lower and top masts was made longer than usual and an extra yard was added below the cap which could then be raised or lowered on its parral between the cap and the top. Above this the now shortened topsail was lowered to the cap as before. This was the origin of the double topsail, later to be followed by the double topgallant. Donald McKay fitted this arrangement on the famous Great Republic. This simple division of the sail was easier to work, and quicker, than the old single topsail as the upper topsail yard could be lowered from the deck and its sail then fell in front of the lower portion and was blanketed by it, the men then going aloft to furl it.

  Another American shipmaster, Captain Howes, next brought out an improvement on this arrangement in 1853. In his version the new lower topsail yard was fixed to the lower mast cap with amovable crane and was additionally supported by an iron bar from the top. It would not move up or down however. The upper topsail on its still hoisting yard had its foot cut without any roach and was laced directly to the jackstay on the lower topsail yard without any gap, thus presenting an appearance as of a single topsail. The upper sail could be lowered quickly, thus saving the arduous task of reefing as with the single topsail, although it still had to be taken in and furled. This was but a step from the true double topsail first adopted in British clippers in 1865 with the Ariel, whereby the two sails were separate entities, with a slight gap between them.

  In Howes' rig, when the upper portion was furled on its own yard, its foot was still laced to the lower yard. With the true double topsails however, the upper was furled completely on its own yard. Occasionally some captains still laced their upper topsails down as close as possible to the lower yards.