TABLE, showing the number of Threads and Weight of Hawser-laid Rope, three strands, tarred, 113 fathoms. Signal-halyards stuff is made of strands that have been laid up in opposite ways, so as to lessen that tendency to taking in turns which is so inconvenient in hoisting flags. It is laid up in lengths of 113 fathoms, and from to 14 inch in circumference. BLOCKS. Ship's Blocks are made of elm, having either metal or lignum vitæ sheaves, with a metal bouching and iron pin. Their size is denoted by the length of the shell, and their quality by their degree of flatness or thickness, number of sheaves, scores for stropping, and nature of stropping. For instance, a brace block is (say) 20-inch, single, thin, and double scored. A tye block is, single, thick, and iron bound. Clump Blocks are made shorter and thicker, and have metal sheaves, which are smaller in diameter than those of other blocks which reeve the same sized rope. Shoulder Blocks, such as purchase ones, are made with a projection left on the shell, which prevents the falls from being jammed against the sheers, &c. The Fiddle Block is a large and small single block made on end in one piece, each being equally large in the swallow. The parts of rope are kept more clear of each other in this kind of block, and as they do not cross, there is less friction; but as the upper sheave is smallest in diameter, there is a loss of power. Sister Blocks are also two in one on end, but are of the same size. They are only used where two different ropes lead from similar directions, but well apart, as in the case of topsail lifts and reef-tackles. Iron stropped blocks have either a swivel or standing hook. In the case of snatch blocks, the binding is cut through to receive the rope, and is connected by a clamp, which should be locked whenever the rope is rove. Blocks should frequently be examined, not only as to strapping, but also by knocking the pin out, and inspecting the bouching. The loss of power, and strain on rope occasioned by a worn bouche is considerable. The working blocks of tackles, * In fitting flags, Sennit distance lines are less liable to take turns than is rope of any kind, |