《天工开物·中篇·舟车》
粮船的中桅帆一般需要十个人一起用力才能将其升到桅顶，而头帆却只要两个人便足够了。
粮船中桅篷合并十人力方克凑顶，头篷则两人带之有余。
The middle mast sail of a grain ship generally requires ten people to lift it to the top of the mast, while the head sail only needs two people.