Page:The New International Encyclopædia 1st ed. v. 03.djvu/509

* BBEAKEK. 447 BKEAKWATEB. Shoals are invariably covered with breakers in heavy weather, and a very moderate swell will break over rocks or shoals only a few feet below the surface. The calls breakers ahead, on the lee bow, on the starboard bow, etc., indicate that breaking waves are seen in the direction indi- cated; breakers often serve as a warning of a shoal which might be unnoticed in a very smooth sea. BREAKING BULK. A breaking open of a package, bundle, box, or the like, of chattels, and appropriation of the contents thereof to the uses of the person who breaks it open in such a man- ner as to amount to a conversion, a violation of the rights of the owner, or the like. At common law, a bailee who received goods inclosed in a box or a package was not liable for trespass or theft if he sold the box or package and its con- tents; but if he broke open the box or package, and sold a part or all of the goods, he was crim- inally liable. The reason for this distinction seems to have been that the bailor delivered pos- session of the bo.x or package to the bailee, but he did not deliver possession of the goods inside. Hence, when the bailee sold and delivered the bos or package there was no wrongful taking, but there was when he broke open the box or package and disposed of the contents which had not been delivered into his possession, ilodem legislation in England and many of the United States has abolished this distinction, and has de- clared the fraudulent conversion of the bailor's goods by the bailee to be larceny (q.v.), whether attended by breaking of bulk or not. See Breach; L.rceny: Coxt;bsion; Sale; and con- sult the authorities there referred to. BREAKWATER (anything that breaks the force of the waves). A barrier intended for the protection of shipping in harbors and anchor- ages. It sometimes happens that in front of a semicircular bay a small island is so situated as to form a natural breakwater. This is to some e.xtent the case with the ports of Portsmouth and Southampton, England, which are protected from the south by the Isle of Wight. In most places, however, bays and harbors are without such nat- ural protections, and it is often found necessary to construct artificial breakwaters to prevent the entrance or formation of waves from the sea to disturb the shipping anchored within. It is with the design and construction of these arti- ficial breakwaters alone that we shall deal here. Breakwaters may be divided into two main groups : ( 1 ) Those which give shelter and pro- tection to commercial harbors or their entrances, and (2) those which shelter an anchorage or roadstead for vessels in transit which have occa- sion to escape from the violence of passing storms. Such anchorages are usually termed harbors of refuge. (See Harbors.) Each of these two classes may be technically further di- vided, according to their particular type of con- struction. To discuss in the case of each of these types its theory of action and conditions of application, involves technicalities which are suitable only for special engineering treatises, but a brief definition of each is possible. The types are as follows: (1) Attached breakwaters are those which project from a cape or headland; (2) insular breakwaters are those which arc wholly detached from the mainland; (3) per- manent breakwaters are those which are rigidly sii)ported on the bottom of the sea (the major- ity of breakwaters arc insular and permanent) ; (4) lloating breakwaters are those which are upheld by the water, being simply anchored to the sea bottom; these are seldom employed; (5) reaction breakwaters are those so construct- ed that the oviter slope breaks the surface of the waves, while the inner slope regulates the cur- rents; (6) composite breakwaters are those which consist of an upright wall resting on a comparatively wide and flat mound of loose stones. Examples of each of these types will be described Ijclow. The design and position of a breakwater in all cases are determined by the direction and amount of wave-force which it will liave to resist. Gen- erally speaking, the height and force of the im- pinging wave's in any locality depends upon the force and direction of the winds, the depth of the water, the fetch or distance over which the waves move, and the angle of incidence at which they strike the breakwater. Some very notable instances of wave-force are on record. In the Wick Bay Breakwater, in England, « concrete block 45 feet wide, 26 feet long, and 21 feet high was completely turned around on its base and finally tipped off its foundation. This block weighed 1330 tons and fonned the end of the breakwater. It was replaced by a larger block weighing 2600 tons, which was in turn carried away by the waves. Experiments made by Thomas' Stevenson, an English engineer, by means of marine dynamometers to record the pressures, showed pressures of 6000 pounds per square foot in the Xorth Atlantic Ocean, and of 3000 pounds per square foot in the German Ocean. At the time that the beacon at the mouth of .the River Loire, in France, was destroyed, il. Le Fernie calculated that the wave-force im- pressed upon the work must have exceeded 4800 pounds, and approximated 6000 pounds, per square foot. To determine the wave-pressure on the breakwater in Lake Ontario at Oswego, X. Y., Mr. Wm. P. Judson, civil engineer, attached dy- namometers to its face at the water's surface, at 8 feet below the surface, and at 8 feet above the surface. The pressures recorded were : At 8 feet below the surface, 10 pounds per square foot : at the surface, 600 pounds per sqiiare foot: and at 8 feet above the surface, 1000 pounds per square foot. The foregoing are isolated instances of wave-pressures, and cannot be assumed to be of general application; they serve simply to con- vey some idea of the forces imposed upon break- waters by action of waves. In closing this refer- ence to wave-pressures, it should be carefully noted that the angle at which the waves strike the breakwater has much to do with the pres- sures exerted. For example, by reducing the angle at which the waves struck the Wick Bay Breakwater from 90° to 80°. the structure with- stood safely the action of the waves which pre- viously had repeatedly destroyed it. From this brief consideration of the wave-force acting upon a breakwater, it is evident that its design from the standpoint of stability must depend upon conditions arising from the location of the work. In considering typical examples of break- waters, one of the largest and most expensive is the Cherbourg Breakwater, which was built to protect the crescent-shaped bay forming the great French naval port of Cherbourg. Its con-