WINTER CLIMATE. 341 



above the southern horizon for an instant at 

 February 7th. February 24th was the coldest day, 

 the thermometer sinking forty-five degrees below zero. 

 April 3d, the ice was seven feet thick. In the beginning 

 of May it attained its maximum thickness of seven feet 

 nine inches. June 12th, the thermometer rose to 55, 

 the highest point of the season. Two days after, the 

 first rain fell. At the end of June small streams of 

 water began to flow from the land. At the end of July 

 the sea-ice was diminished to a thickness of four feet by 

 the melting of the upper surface. August 8th, the bay- 

 ice broke up, and set the ships free, after eleven 

 months' close detention. Four days afterwards, the 

 young i:e began again to form on the sea at night. 



Throughout this winter of intense cold, the tempera- 

 ture of the sea remained nearly uniform. It never sank 

 so low as twenty-nine degrees. A hole was kept open 

 through the ice, near the ships, for the purpose of 

 observing the water, as well as for noticing the rise 

 and fall of the tides. The ice invariably increased its 

 thickness by additions to its lower surface. As the 

 Bea-water froze, a considerable portion of its salt was 

 separated from .it, and blown along the surface of the 

 ice, mixing with the fresh-fallen snow as it went. On 

 this account snow-wreaths could never be used for 

 melting into water ; the snow on the land often con 

 tained traces of salt, miles away from the sea. The 

 sea-ice hardly ever contained more than one quarter the 

 quantity of salt found in an equal volume of sea-water. 



The interior of the ships was warmed to between 

 forty and fifty degrees. This was found to be the 

 highest limit of safety ; in it, the hoar-frost was never 

 thawed in the beds ; the blankets and night-caps of the 

 sleepers often adhered inconveniently to the ships' 

 planks. With a higher temperature, the vapor of the 



