about eleven o'clock
It was difficult to breathe , what with the heavy , oppressive air and what with the fall of suffocating snow , constantly growing thicker . Horses slipped and went down , but were raised again ; fresnos were mired , but freed once more ; men gave out and were sent to their camp . And the fight kept on . But about eleven o'clock Bryant felt a cool puff of air on his cheeks , light and of brief duration . It was followed by a second , this time quicker and stronger , blowing from the northwest and sending the snow a-scurry in a slanting fog of flakes past the flames of the torches . He studied this change for a moment , then sought out Carrigan . `` Time to make a break for cover , '' he announced .