The arms are made in the same way as the shank. They are rounded and flatted on the different sides, so as to resemble the shank, and are of the same diameter as the shank at the throat and small round. The ex tremities of the arms are scarfed in the same way as that part of the shank to which they are united. The arms are rounded between the throat and the palms, which are nearly in the middle of the arms ; and from this it has a square, called the blade, tapering to the bill on the flatted side, and a square nut is made on the inner round ed side for receiving the palm, that the palm when shut on may project its thickness at the base or inner part, the exterior part forming a straight surface with the peak or bill. The outer side of the arm is made straight from the rounded pail or haunch to the snape or bill, and there kept to half the substance of the inner part. The snape, which is nearly one-fourth the breadth of the palm, resembles the bill of a duck. The interior part of the arm is made new ly a straight line from the throat to the bill. It is reckoned stronger from having a small an gle in its length, the vertex of the angle being,in the mid dle of the arm. A line drawn from the trend to the point of the bill forms an angle of nearly 60 degrees with the shank.
The palms or flukes are two thick plates of iron, nearly resembling an isosceles triangle, and formed of different pieces, well wrought and perfectly sound ; otherwise, in the process of welding them on the arm, they are likely to separate at the parts where they are joined together. The sides of the triangular palms, which are a little curved, are from one and a fourth to one and a half inches longer than their base, and the highest points of the curves about the same distance, from a straight line drawn from the extremity of the base to the vertex of the triangle. The base is straight ; the inner flat surface is a little curved in its breadth, but is a straight line in its length.
The stock of anchors consists of two beams of oak firmly united by iron bolts and hoops, two hoops being on each side of the middle, and one near each extremity. The length of the stock is equal to the length of the shank, and half the diameter of the ring. Its breadth and thickness in the middle, are each one-twelfth of its length. At the extremities of the stock, the breadth and thickness is onr twenty-fourth of its length. The upper surface of the stock next the ring is always straight, or forms one continued plane. Fig. 5. The under surface is composed of three planes. The central ore exit nds to half the breadth of the stock, on each side of the middle, and from that place the surface descends to each extremity. Lest the wood should shrink, an opening of an inch and a half is generally left between the two beams of oak, that the hooks which bind them together may be driven nearer the middle.
When the various parts of an anchor are thus formed, the next process is to combine them together. The square which receives the stock is welded on the ex tremity of the shank, and the ring, whose thickness is half the diameter of the small round, after being forged, is introduced through the opening in the square, and its extremities well joined together. The arms are then welded to the shank by means of the hcrcules, and the palms by the same means are joined to the arms. When the arms are welded to the shank, the whole crown of the anchor is, by repeated welding heats, made per fectly sound, and worked to its proper proportion. It is then finished by working it with hammers till it is quite cold. This part of the process adds much to the ap pearance of the anchor, and hardens the surface, so as in some measure to retard its corroding.
As the process of making anchors is a very severe trial to the iron, it should be of the very best quality. While the anchor is heating, the external bars get into a weld ing state much sooner than the internal ones, and there fore they are much more liable to be injured by this part of the process. By examining the broken parts of large anchors, which have been made of iron of an inferior quality, it is very manifest that their strength has been much diminished by being brought to a great er heat than what was necessary. When this is the case, the anchor breaks very short, and none of the in ternal bars appear, in consequence of their having been consolidated, by over heating, into one mass. But when anchors that are made of the best iron, and not over heated, are exposed to a strain which they cannot resist, they will in many instances bend, and crack on the sur face of the shank or arms. When this happens, the centre bars, both in large and small anchors, are always distinctly seen, in consequence of not having been con solidated by an excess of heat. Hence we are of opinion, that if an anchor large enough for men of war, or East India ships, is perfectly sound, or consolidated in the shanks or arms, from 21 to 32 inches from the surface, it is less liable to break, than when it is made one solid body throughout, as this is more likely to be effected by over heating than by the process of hammering. The greatest care, however, should be taken that the scarfs of the shank and arms, and that every part of the anchor be perfectly sound ; for if any chinks are left, the salt water will find its way through them, and rust the internal bars. The part which contains the water will also swell, and, by producing a separation of the surface, will render the anchor unfit for service.