ANCHOR. A heavy iron hook of great strength, used to hold on a ship to the ground, and fasten itself in a certain situ ation by means of a rope. Too much importance cannot be attached to the me chanism and construction of anchors, for upon these depends the safety of the ship, especially on lee shores, where otherwise the vessel may be stranded or wrecked. The earliest anchors were doubtless heavy stones, around which a rope passed, and which,. by its weight, retained the vessel in its_palace. The Chinese use crooked pieces of heavy wood at the present day. The action of the modern anchor is to bite the ground, and from the direction of the strain upon it, the anchor cannot move without plough Ina up the ground in which the fluke or hook is sunk. When this unhappily oc curs, it arises from the softness of the ground, or the violence of currents and waves. The ship is then said to drag her anchor. When well anchored, the cable will break, or the fluke will be snap ped off and left in the soil, rather than loose its hold. Anchors have different names, according to their sizes and the 'purposes they serve, as sheet, best bower, small bower, spare, stream, and kedge anchor. The largest ships have seven anchors, the smaller, as brigs, cutters, and schooners, only three or four. The ma, nufacture of anchors requires great know ledge of the structure of iron, and skill in manufacturing it.
The shank of an anchor is made long, so that the stock, or cross-piece, near the cable-ring, may have greater power in di recting one or other of the arms down wards : where it joins the stock it is square to receive and hold the former securely. lii the square part is a hole for receiving the ring for the cable. The arms form an angle of 56° with the shaft, they arc rounded for the first half of their length, and the remainder is flattened out and is called the blade. The length o'f the arm is nearly half the length of the shaft. The stock is generally formed of two oak beams embracing the square, and finnly united by nuts, iron bolts, and hoops ; occasionally it is made of wrought iron, and then it passes through a hole in the square.
The weight of anchors for vessels is generally apportioned to the tonnage, the weight of the anchor in hundred weights being one-twentieth the number of tons of burden,—thus a ship of 1000 tons would require a sheet-anehor of 50 cwt. In the English navy 1 cwt. is allowed for every gun ; an 80 gun ship will have an anchor of SO cwt. The weight of an 'an chor ten feet long, is 11.4 ewt, and if all forms of anchor be the same, the weights would be as the cubes of the lengths : hence the weight of an anchor be found by multiplying the cube of its length by •0114. This gives a sufficiently close approximation • but for large an chors this is too small, because the thick ness is greater in proportion.
Anchors have been made with only one arm. Mr. Stuard patented one of this kind some years ago. To insure the an chor falling the right way, with the fluke down, the shank was shortened, so that when suspended by the cable, it will cant the most, and when it has hold in the ground, the ship will ride more safely, as a long shank is more likely to be bent, or broken from its hold. The bars which compose the anchor are put together in one length, there is no welding together, and its strength is thus much increased. The great object in anchors is to provide the greatest strength, by preserving such a disposition of the fibres of the metal as shall conduce to this. The crossing or
bending of fibres at the junction of the flukes with the shank and with the crown should be avoided, as great strength is required in these parts. In this re spect most anchors are defective, for in connecting the shanks with the crown pieces, the grain of the metal is crossed or curved, so as to strain the fibre and induce a weakness. Mr. Piper, in 1S22, proposed new forms and constructions to meet and overcome this objection. Mr. Rodgers, Lieut. R.N., England, in 1846 patented an improved construction of stocks, shanks, arms and palms of an chors, in such a manner, that they will, with the Mille weight of metal, be stronger in'the direction in which the strain comes on them, and have greater holding power than any which have hi therto been used. The term is based on the principle of the wedge, which is a cross-section of the stem or shank, and being of a rectangular form, is better cal culated to resist the strain to which that particular part is subjected, than any an chor of the usual form. The stem is re duced at the end next the stock, where the principal strain being torsion or twist ing, it is better suited to resist than any other. The arm is wedge-shaped, the outer circumference of the are being broader than the inner, thus disposing of the metal so as to obtain the greatest amount of strength, and at the seine time have a greater holding power by the pres sure of the soil on the sides of the arms. The palms are made with the bevelled sides in front instead of the back, as hi therto: this also produces a greater hold ing power, for in dragging the anchor he found, from actual expenment, that the soil fills Up behind the palm, and prevents the water entering the rut. In applying one part of this invention to anchors al ready made, a piece of iron is welded on to the front of the arm to form the palm, the parts projecting beyond the arm being bent back, and forming the bevelled sur faces, which will have a similar effect to that already described when the palms arc forged out in the solid.
Anchors arc sometimes liable to be dis turbed by gromui ice being formed at the bottom of the water ; this occurs when the temperature is lower and the water not deep. Anchors to which buoys have been attached, have been raised in the Baltic sea owing to this cause, and stones, from 3 to 6 lbs., have been floated to the surface by the lifting power of the ice. Under such circumstances, the slow for mation of ice round an anchor tends to give it a lifting power and make it rela tively lighter, so that upon a slight mov ing force applied to it, or even upon a further formation of ice, the anchor gra dually rises out of the soil.
AN ClIOVY. Small soft-finned fishes of the herring species, inhabiting the tropi cal seas of this continent and India. They arc caught in the Mediterranean sea in abundance from May to July, the fish then leaving the Atlantic to deposit their spawn on these shores. The fishing is carried on by night, the anchovies being attracted by the charcoal fires which are burned in the stern of the -boats. The head, gills, and entrails arc removed, and the bodies salted and packed in small casks, from 5 to 25 lbs. weight, and if the air have been excluded, they will keep good for any length of time.