416 



SCIENCE. 



[Vol. IV., No. 91. 



same-sized chain, to which is attached, in 

 some cases, a three- thousand-pound mushroom 

 anchor, which is shaped like an open inverted 

 umbrella, and in many cases a stone-sinker, 

 as shown in the cut. The buoy is separated 

 by diaphragms into several water-tight com- 

 partments, so that one of them may be punc- 

 tured without sinking the buoy. They are 

 made of boiler-iron, and are tested by hydro- 

 static pressure before being placed in the 

 water, and they will stand much hard usage. 



When these buoys are lifted from their as- 

 signed positions by ice, they carry their moor- 

 ings with them, and, when left b} 7 the ice, have 

 sufficient buoyancy to float these accessories, 

 though under such circumstances thej r are sunk 

 somewhat below their ordinary line of flota- 

 tion. The} 7 show a surface, at most, of eight 

 by six feet above water, while the mushroom 

 anchor it is dragging must be fully one hun- 

 dred feet below water. Hence the winds can 

 have little effect on the motion of the buoys, 

 in comparison with the ocean-currents. 



The whistling-buoy differs from the ordinary 

 sea-buoy in having a hollow tube from eigh- 

 teen to forty-five feet long thrust through it 

 and down into the still water, while it is 

 surmounted by a steamboat- whistle. As the 



to six months, according to its size, without 

 being refilled. 



As the government pays those who pick up 

 any stray buoj r a reasonable price for their 

 trouble, they are often brought into port. 



Fig. 3. — Pintsch gas-buoy. 





Fig. 2. — Courtenay's whistling-buoy. 



buoy rises, the air is received into the tube 

 through a set of ingeniously arranged valves. 

 As it sinks, the air is forced out through the 

 whistle. 



The lighted or gas buoy is filled with com- 

 pressed illuminating-gas, and is surmounted 

 by a protected burner. It will burn from three 



The position of each of the stray buoys so far 

 reported, and the prevailing currents so far as 

 known, are shown on the accompanying chart. 

 The buoys are plotted and numbered to cor- 

 respond to the paragraph below, which gives 

 such history of the buoy as could be obtained 

 from official sources. The buoys are not num- 

 bered consecutively, but in the order in which 

 the writer heard of each being sighted. 



1. Whistling-buoy, recently adrift, as the paint was 

 still fresh when it was sighted, May 17, 1881. 



2. Sighted June 15, 1884. Same as No. 19. 



3. Can-buoy of the largest size, picked up March 

 17, 1881, near Bermuda; supposed to have come from 

 New- York Bay. 



