steaming against her anchors, with engines at full power, but the anchor is stated only to have moved slightly to get a better grip, and then resisted all efforts to pull it out. When getting up anchor, the ship is, of course, right over her anchors, and so is able to break them out of the ground. At least 90 per cent. of anchors now made are stockless.

Sea Anchor. This is an arrangement well known to those who go to sea, and particularly those who have been wrecked, or who have had to take to the sea in an open boat. It is intended to break the force of the waves, in bad weather, so that a boat can ride out a storm in comparative safety. It consists of any spars that are available, any sails, and any weights &c., that can be obtained. The spars are lashed together, the sails with them, and the weights slung from them. The boat is made fast to a span connected to the two ends of the arrange ment, and rides behind it, just as she would behind an anchor. The best position for a boat, in a seaway, is head on to the sea, the waves breaking at her bows and going right over her. They do less damage in that way than if they are allowed to take the boat broadside on.

The sea anchor helps the boat to keep the position, head on to the waves, and it breaks the force of the waves as they come up.

Anchorages. This term denotes the methods of attachment of ropes and chains to their drums, or to rigid fixtures; the fast ends of brake straps, the attachment of the chains of suspension bridges into their piers, and similar instances.

Anchor Crane.-A light crane used for lifting ships' anchors. It is of triangularframed type, comprising post, jib, and single or double tie rods. All dimensions for these members are given by "Lloyd's" for anchors of different sizes, ranging from 20 to 60 cwt.

height named. For anchors of 15 cwt. and below, the height is 15 feet. If above 15 cwt. the height is 12 feet. Anchors of Admiralty pattern are dropped successively from two positions, one with shanks and arms horizontally, the second with the crown downwards, two iron blocks being placed under it, these being of sufficient height to prevent the crown of the anchor from touching the slab.

If these tests are passed, the anchor, or piece, is slung up, and hammered with a sledge weighing not less than 7 lb., and it must give a clear ring such as to satisfy the inspector that all the parts are sound.

A cold bending test is made on a piece 8 inches long, cast on, and cut from each casting, and turned to 1 inch diameter. It is then bent cold by hammering through an angle of 90 deg. over a radius of 1 inches, without showing indications of flaw or fracture. If this fails, the anchor is condemned. In some cases the piece is cast large enough to permit of cutting four test pieces.

Anchors are annealed, during a period of from three days for small sizes, to six days for those of large size. They are then stamped "Annealed Steel." But Lloyd's inspectors examine the castings also before they are annealed, in order to detect any cracks or other defects which might not be so obvious subsequently to annealing.

Angle (from Latin angulus, a corner).In geometry an angle is the inclination of two straight lines to one another, which meet together, but are not in the same straight line. Angles are measured by the number of degrees they contain, the right angle, containing 90°, being the standard by reference to which other angles are compared. An acute angle contains less than 90°, and an obtuse angle more than 90°.

In the first book, Euclid gives some valuable axioms relating to angles, summarised below.

1. The angles which one straight line makes with another on the same side of it are together equal to two right angles.

2. The greater side of every triangle has the greater angle opposite to it.

3. If a straight line falls on two parallel straight lines, it makes the alternate angles equal to one another.

as above, and bisect the angle BAC by the line AD. BAD is an angle of 45°.

An angle of 60°. With centre A and any convenient radius describe the arc CD. From D with the same radius cut CD in E. Through E draw AF. BAF is an angle of 60°. An angle of 30°. Construct an angle of 60° and bisect it. Then the angle BAG is an angle of 30°.

An angle of 15°. Construct an angle of 30° and bisect it. BAH is an angle of 15°.

An angle of 75°. Erect a perpendicular AE. With centre C and the same radius as that used in erecting the perpendicular describe an arc cutting DE in F. Join AF. Then the angle BAF is an angle of 75°.

shape and has two angles of 45° and one of 90°. The set square of 60° contains angles of 90°, 60°, and 30°. The following diagrams, Fig. 65, show clearly how these two set squares, alone, and in combination, may be arranged to make almost any angle.

Angle Bending Machine. There are several special types of machines made for this purpose, distinct in character from bending machines used for plates and sheets. The latter may be used for some classes of angle bending, by inserting narrow rolls at one end of the rollers, grooved to take angles and tees. But these are only makeshifts, and not suitable for all bends.

Angle bending machines deal also with tees,

An angle of 120°. Produce BA to C. At A make an angle CAD of 60°. The angle BAD will therefore measure 120°.

=

An angle of 150°. Make BAC a right angle, 90°, and CAD an angle of 60°. BAD contains 150°. Other angles may be similarly constructed:-105° 60° +45°; 135° = 90° + 45°. Practically all the angles the construction of which is described above can be made with set squares in much less time, and, with due care, with equal exactness. The point to remember is that the angles made by one straight line which stands on another are always equal to two right angles or 180°. The two set squares in common use are those of 45° and 60°. The former is the half of a square in

channels, H sections, and bars, by changing the rolls. The axes of the rolls are vertical, see Fig. 66, Plate V., so that there is no limit to the length of bars which can be passed through them. The relative positions of the rolls are adjustable to suit different curvatures. They can be changed to accommodate various sections that have to be bent. They are driven by spur gears situated below the table, over the surface of which the bars slide. The rollers in the best machines can be raised and lowered to admit webs of different thicknesses between their bottom edges and the table. In some cases the roll is in two parts, the upper adjustable on the lower to admit various thicknesses of web. The lower