1876 POWER OF THE SUN. 7 



below. The gravel and cinders strewed over the floe 

 near the ship, to hasten its decay, have at last com- 

 menced to eat their way down through the ice. This 

 is more than a month later in the season than the 

 same event occurred at Melville Island in latitude 

 75 0' in 1853. 



' It would appear that the sun, unassisted by other 

 causes, is, after a cold winter, not sufficiently powerful 

 to produce a thaw on a snow-clad ground until it 

 attains an altitude of about thirty degrees ; if this is 

 the case, then at the North Pole it is doubtful whether 

 the snow ever becomes melted. At the South Pole, 

 where the climate is little affected by warm ocean 

 currents, no thaw can ever take place.' 



The 21st proved to be the warmest day of the 

 year at Floeberg Beach. The sun having then an 

 altitude of 31, the same that it has at London on the 

 12th of March and the 2nd of October, the black bulb 

 thermometer exposed to the sun's rays registered a 

 temperature of 128 degrees. In the sheltered position 

 of Discovery Bay and with a southerly aspect, a similar 

 thermometer registered the same temperature on the 

 6th of June when the sun was the same height above 

 the horizon. In May when the sun attained an altitude 

 of twenty-three and-a-half degrees, the height it reaches 

 at the Pole at midsummer, the greatest amount of 

 heat registered by the black bulb thermometer was 

 95 degrees. The thaw, however, is as much dependent 

 on warm southerly winds as on the direct heat of the 

 sim at the place. 



' 2bth. The gale died out this morning, leaving 

 the temperature at 39. Several ducks were observed 



