The sea-mans dictionary, or, An exposition and demonstration of all the parts and things belonging to a shippe together with an explanation of all the termes and phrases used in the practique of navigation / composed by Henry Manwaring ...

Blocks.

Are these small wooden things, having Sheevers in them, wherein all the running-Roapes doe run. There are divers kinds of blocks: as single Blocks, double blocks; Blocks with 3,4, or 5, shee∣vers in them, and they are called by the names of Roapes whereunto they serve. As the sheate Block, the tack-Block, the fish-Block, &c. Note that double-Blocks, doe purchase more then single-blocks, and there∣fore in all places where we have occasion to use strength with few hands, we have double-Blocks (as to the Tacks of our Ordnance:) But you must note also, that though double-blocks purchase with more ease, yet

single-blocks doe purchase faster: When we hale upon any Tackle, Halliards or the like, to which two Blocks doe belong, when they meet and touch, we can haile no more, and this we call Block and Block.