The annexed figure represents an improved cat block, invented by Mr. Bothway, and rewarded by the Society of Arts. The advantages which this block possesses over those in common use, are thus stated by Mr. Bothway. " In all large class ships in the royal navy, the unwieldy nature of the usual cat-block requires that two men should be sent out on the anchor, a most perilous service in rough weather ; whereas mine only requires one man at any time, because he has not to sustain the whole weight of the block, as in the former case, but only that of the hook. And in vessels smaller than line of battle ships, in blowing weather, when the ship pitches heavily, the anchor may be hooked without a man going on it, by his standing on the head, and guiding the book of the block to the anchor, by a staff and hook, similar to a boat-hook. This facility is gained by the mobility of the swivel in its socket, so that the man has not the weight of the block to turn, in order to insert the hook in the ring of the anchor. Should the anchor, when hooked in the dark, or otherwise, cause a turn in the fall, the hook being on a swivel joint, the turn will come out before the strain comes on the block ; and when the anchor is foul it can also he hooked with great facility. In my thirty-two years' service I have seen the wooden cat-blocks swell so much in cold climates, that the sheaves have become immovable ; mine, being of metal, are liable to no such inconvenience." Another great advantage may be derivable from Bothway's cat-block being applicable to other uses; whereas the old ones are not. For instance, by merely having a spare socket or two fitted with hooks of various sizes, it may take a strap for gear-blocks, or it may be converted into a lashing block without the hook and socket, but with the socket bolt. In the figure, which represents a perspective view of the block, it will be seen that the hook, instead of being formed in one with the strap, turns with a swivel head, in a socket which hangs from a pin passing through the lower end of the shell. Although entirely formed of metal, they are li&hter than wooden ones with their iron bindings, and capable of the same service.
There is another species of blocks, which are termed "Dead eyes," and are used for tightening or setting up, as it is called, the standing riming of ships. It
consists merely of a circular block of wood, with a groove on its circumference, round which the lower end of the shroud, or an iron strap, is fastened; three holes passing through the face, (ranged in a triangle,) to receive the laniard or mailer rope, which forms a species of tackle for tightening the shrouds., There are no sheaves in the dead eye, but the edges of the holes are rounded off to prevent cutting the laniard, but this very imperfectly answers the Purpose; as from the roughness of the grain of the wood, which is usually elm, and from the stiffness of the rope, the laniard renders with difficulty, and from the great strain to which it is subjected, it is frequently broken. A very simple and effectual improvement has been made in this respect by Mr. Carey, Surveyor of Shipping, at Bristol, by inserting a half sheave of lignum vita into each of the holes, which causes the laniard to render with greater facility, and the shroud to be set up in half the usual time. Fig. 1 shews the dead eye ; Fig. 2 a section of the same ; and Fig. 3 one of the half-sheaves. It will be seen from the manner of inserting the half sheaves, as shown in Fig. 2, that they cannot fall out, for the more pressure there is on them, the faster they will be.
The annexed figure represents a block of a peculiar description, intended for forming a kind of rope-road to a stranded ship. When a vessel thus circumstanced has had a rope thrown over by Capt. Manby's apparatus, or any other means, considerable difficulty has been found in reeving an ordinary pulley for the conveyance of the crew to the shore. In the figure, it will be seen that the pulley divides at the hook, or shackle, into two equal parts, so that it may be instantaneously passed on to a stretched rope, and, by means of a cord from the ship, persons may pass securely and quickly backwards and forwards. The little bar which traverses the opening is fixed at one end by a joint, and fits into a mortise, as shown ; the use of it being to confine the rope in its place, when any vehicle, or other apparatus, is slung or suspended to it.