The steamer on reaching the given position lowers one, or perhaps two, mark buoys, mooring them by mushroom anchor, chain and rope.
Using these buoys to guide the direction of tow, a grapnel, a species of fivepronged anchor, attached to a strong compound rope formed of strands of steel and manila, is lowered to the bottom and dragged at a slow speed, as it were ploughing a furrow in the sea bottom, in a line at right angles to the cable route, until the behaviour of the dynamometer shows that the cable is hooked.
The repair being thus completed, the various mark buoys are picked up, and the ship returns to her usual station.
The harbour of Port Blair is well supplied with buoys and harbour lights, and is crossed by ferries at fixed intervals, while there are several launches for hauling local traffic. On Ross Island there is a lighthouse visible for 19 m.
Sand bars keep filling up the mouths of these channels, necessitating frequent dredging and extension of the breakwaters, work undertaken by the Federal government, which also maintains a most comprehensive and completeystem of aids to navigation, including lighthouses and lightships, fog alarms, gas and other buoys, life-saving, storm signal and weather report stations.
This fact having been fully demonstrated, acetylene dissolved in this way was exempted from the Explosives Act, and consequently upon this exemption a large business has grown up in the preparation and use of dissolved acetylene for lighting motor omnibuses, motor cars, railway carriages, lighthouses, buoys, yachts, &c., for which it is particularly adapted.
This and other points on the route were marked by buoys laid after careful triangulation by Capt.
Lights and Buoys.-In view of the difficulties attending navigation in the Gulf, and the impossibility of arranging with the Governments of the littoral for the provision of lights and buoys except on terms which would have greatly hampered shipping, the British Government, in view of the great preponderance of British shipping in the Gulf, has established since 1912 a very complete system of lights and buoys, the cost of which is shared in equal moieties by the Government of India and H.M.
Lighthouses exist on one of the Quwain group of islands off Ras Musandam and on Tunb I.; light-buoys have been placed at Bushire in the outer and inner anchorages, at Bahrein and on the Shatt al 'Arab bar.
Shore lights and unlighted buoys have also been provided where necessary.
They burrow in the sands of every shore; they throng the weeds between tide-marks; they ascend all streams; they are found in deep wells, in caverns, in lakes; in Arctic waters they swarm in numbers beyond computation; they find lodgings on crabs, on turtles, on weed-grown buoys; they descend into depths of the ocean down to hundreds or thousands of fathoms; they are found in mountain streams as far above sea-level as some of their congeners live below it.
The ocean of water buoys or floats the ship, and the ocean of air, or part of it in motion, swells the sails which propel the ship. The moving air, which strikes the sails directly, strikes.
Its specific lightness, combined with strength and durability, recommend it above all other substances for forming life-buoys, belts and jackets, and in the construction of life-boats and other apparatus for saving from drowning.