BUOY. 676 BUOY. the action of tlis waves (there is no clapper, but iron balls roll about on a plate under the bell's mouth, and striking against the inner surface of the bell, make a noise that can be heard at a considerable distance) ; and tchistling tain important channels, thus permitting the safe entrance and exit of vessels at night. They are provided with a reservoir of compressed illu- minating gas under a pressure of 150 to 180 pounds i)er square inch, which is sufficient to last from 85 days to a year, according to the size of the buoy and the degree of compression of the gas. The cost is estimated at less than seven cents per day (the light is not extin- guished night or day) and the reservoir may be filled in a few minutes by means of a hose 1 AXD 2, CAN BOOTS ; 3, NTT OH NCN BUOY. iuoys, which are fitted with an apparatus by which air compressed by the movements of the waves is made to escape through a whistle, and so gave warning of danger. Cages or shapes are sometimes put on buoys as further marks of dis- tinction. In the United States the following system of placing buoys as aids to navigation is prescribed by law: Red buoys mark the starboard or right- hand side of a channel when coming from sea- ward, and Hack the port or left-hand side; mid-channel dangers and obstructions are marked with danger buoys, having black and red trans- verse stripes, and mid-channel buoys marking the fairway have longitudinal black and white stripes ; and wreck buoys marking sunken wrecks are painted green; buoys mnrkinij anchorage limits or dumping limits are painted white. The <}iiarontinc buoy, if there be one. is painted yel- low. The starboard and port buoys are num- bered from the seaward end of the channel in large white or black numbers, odd white num- bers on the black buoys, and even black num- bers on the red. The life buoy now in common use in the navy consists of a hollow copper ring having on each side a long tube swinging freely on a pivot and weighted so as to keep in a vertical position. In the bulb at the bottom there is a burning composition which takes fire upon contact with the water, the gas Inirning at the top of the tube with a bright llame which can be seen at a considerable distance at night. This machine is hung over the side of the vessel near the stem, and is dropped by means of a trigger. An anchor buoy is a small metal buoy made fast to the anchor by means of a rope, and it is used to mark the position of the anchor, so that should the ridingcliain (the chain the s!iip liangs by) part, the whereabouts of the anchor is still indicated by the buoy, and it may be re- covered. Gas buoys are used for marking eer- mj «A8 BUOY. leading from the gas - tanks of the supply steamer or buoy-tender. The body of the buoy is sufficiently large to give proper buoyancy, and is held upright by a centre weiglit at the bottom. On top of it there is a wroughtiron tower, about fi feet high, upon which is mounted a Fresnel lens lantern, which is protected by a wii'e cage. A tilling valve and a regulating valve are provided. The lanterns may be so made as to give flashes of dilVcrcnt duration or of different colors. They nuiy lie seen from 6 to 8 miles. Electrically lighted buoys have been used in United States harbors since 1888. They
