midnight
Taking one of Waring 's cartridge cases , La Salle forced the record into its narrow chamber , and selecting a small strip of pine , -- a part of the thin side of his crushed float , -- he stopped the cartridge with a tightly-fitting wad , and fastened it to the board with a piece of stout cord . On the white board he printed , in large letters , `` Read the contents of the case ; '' and going out , he placed it firmly upright on the summit of the berg . At twelve that night the rain fell fast , the wind blew steadily from the southward , and the undulations of the ice , from time to time , told that , although safe in the very heart of the pack , yet still the field had already resolved itself into its component parts . Towards midnight all fell asleep , being satisfied that no immediate danger threatened them ; but at about half an hour before daybreak , Waring awoke , and placed a few blocks on the smoldering embers . As he waited for them to burst into a flame , he heard the air filled with confused murmurings , unlike any sounds that he had previously experienced . Gradually they appeared to draw nearer , to sound from all sides , to fill the air overhead , and even at last to ascend from the depths below . Strangely sweet , yet sadly plaintive , they at once charmed and terrified the poor boy , weak from his recent illness , and worn with the anxieties of his situation .