108 LIGHT SCIENCE FOR LEISURE HOURS. 



back by impassable barriers of land or ice, but by 

 the serious dangers to which the floating masses of ice, 

 and the gradually thickening ice-fields exposed his 

 weak and ill-manned vessel. Since his time, others 

 have sailed upon the same track, and hitherto with no 

 better success. It has been reserved to the Swedish 

 expedition of last year to gain the highest latitudes 

 ever reached in a ship in this direction. The steam- 

 ship ( Sofia,' in which this successful voyage was 

 made, was strongly built of Swedish iron, and ori- 

 ginally intended for winter voyages in the Baltic. 

 Owing to a number of delays, it was not until Sep- 

 tember 16 that the f Sofia ' reached the most northerly 

 part of her journey. This was a point some fifteen 

 miles nearer the North Pole than Hudson had reached. 

 To the north there still lay broken ice, but packed so 

 thickly that not even a boat could pass through it. 

 So late in the season, it would have been unsafe to 

 wait for a change of weather and a consequent breaking- 

 up of the ice. Already the temperature had sunk six- 

 teen degrees below the freezing-point ; and the enter- 

 prising voyagers had no choice but to return. They 

 made, indeed, another push for the north a fortnight 

 later, but only to meet with a fresh repulse. An ice- 

 block with which they came into collision opened a 

 large leak in the vessel's side ; and when after great 

 exertions they reached the land, the water already 

 stood two feet over the cabin floor. In the course of 

 these attempts, the depths of the Atlantic were 

 sounded, and two interesting facts were revealed. 



