It may here be mentioned that ocean cables are usually made in three sections, called, respectively, the shore-end, the intermediate section and the deep-sea section. It is clear that the submerged conductor needs the greatest protection in the shallow water that surrounds the coast, where it lies on a pebbly or rocky bottom, exposed to the drifting action of currents and tides, as well as to the haling flukes of the anchors of storm-tossed ships. In deep water, on the other hand, there is neither shingly bottom nor violent movement to displace and abrade the cable; for all is quiet and peaceful in the profound depths where the god of the trident holds his court; and hence few coverings and a light armor afford sufficient protection. The wear and tear in the ocean depths is a vanishing quantity when compared with the abrasive effects near coast-lines. Looking at the sections of an ocean cable, the biggest and heaviest is the shore-end, while the thinnest and lightest is that which goes down into the depths of the sea. The lengths of the various sections are determined by the survey of the route, which is always carefully made before completing the specification of the cable. Moreover, as the position of the cable-ship at noon every day is known from its longitude and latitude, it follows that the location of the cable on the bed of the ocean is also exactly known. When a cable is broken either by an upheaval or by a subsidence of the ocean floor, the distance of the rupture from the shore end is determined by an electrical test, after which a repair-ship is dispatched to the spot, when the cable is lifted, the "fault" cut away, a new length spliced on, and the amended cable allowed to settle down into its watery depths. At the present time (July, 1909), there are sixteen cables carrying the work of the North Atlantic, at an average speed of 20 words a minute duplex, or 40 words a minute, counting both directions.