The region of fogs on the Atlantic is also the region of ice; fog and ice together are a greater source of peril than fog alone is, even when a ship is making land. Under the latter condition there is the chance of hearing the warning voice of the “syren,” the reverberation of the signal gun, or the tolling of the fog-bell; steam “syrens,” guns, or explosives of some kind, and bells, are all used as auxiliaries to the lighthouses in overcoming, through the medium of sound, the difficulties which fog opposes against the transmission of light. The sounding machine comes into play, and by registering the depth of water, and bearing testimony to the character of the bottom, affords further protection to the navigator. But the shoals and islands of ice, which, with their outreaching, submerged spurs, come drifting down from the Arctic into the track of the transatlantic steamers, are unprovided with anything which might tell the ship bearing upon them in thick weather of their proximity. Sometimes they may be detected by the echo from the whistle or fog-horn, and by the rapid lowering of the temperature of the water in their vicinity. These signs cannot be always counted on, however. The whistle may be going every twenty or thirty seconds, and the quartermaster posted to the leeward with the little canvas bag and the thermometer with which the sea is tested for temperature; all due precaution may be taken, and yet no warning come of the ice that is ahead. On a clear night a berg rising above the horizon will have the effulgence of a star; on a clear day it will notch the horizon with its dazzling whiteness; in a fog it looms up in the gray like a shadow upon a shadow, and is invisible till the ship is close upon it. [Illustration: A Bell Buoy.]