ALASKA. 27 



gold discoveries. The observations were made with standard instruments, and 

 are wholly reliable. The mean temperature of the months October, 1889, to 

 April, 1890, both inclusive, are as follows: October, 33 degrees; November, 8 

 degrees; December, 11 degrees below zero; January, 17 degrees below zero; 

 February, 15 degrees below zero; March, 6 degrees above zero; April, 20 

 degrees above. The daily mean temperature fell and remained below the freez- 

 ing point (32) from November 4, 1889, to April 21, 1890, thus giving 168 days 

 as the length of the closed season of 1889-90, assuming the outdoor operations 

 are controlled by temperature only. 



The lowest temperatures registered during the winter were: 32 degrees below 

 zero in November, 47 below in December, 59 below in January, 55 below in 

 February, 45 below in March, 26 below in April. 



The greatest continuous cold occurred in February, 1890, when the dailv 

 mean for five consecutive days was 47 degrees below zero. The weather mod- 

 erated slightly about the 1st of March, but the temperature still remained below 

 the freezing point. Generally cloudy weather prevailed, there being but three 

 consecutive days in any month with clear weather during the whole winter. 

 Snow fell on about one-third of the days in winter, and a less number in the 

 early spring and late tall months. 



Greater cold than that here noted has been experienced in the United States 

 for a very short time, but never has it continued so very cold for so long a time. 

 In the interior of Alaska, the winter sets in as early as September, when snow- 

 storms may be expected in the mountains and passes. Headway during one of 

 these storms is impossible, and the traveler who is overtaken by one of them is 

 indeed fortunate if he escapes with his life. Snowstorms of great severity may 

 occur in any month from September to May, inclusive. 



The changes of temperature from winter to summer are rapid, owing to the 

 great increase in the length of the day. In May the sun rises at about 3 a. m. 

 and sets about 9 p. m. In June it rises about 1.30 in the morning and sets at 

 10.30, giving about twenty hours of daylight, and diffuse twilight the remainder 

 of the time. 



The mean summer temperature of the interior doubtless ranges between 60 

 and 70 degrees, according to elevation, being highest in the middle and lower 

 Yukon valleys. 



Speaking of the temperature of St, Michael's and vicinity, 

 Mr. Petroff quotes from Mr. E. W. Nelson's report (1880) to 

 the Chief Signal Officer: 



During the past four years, the first mush-ice has begun to form in the bavs 

 from the 15th to the 18th of October, and the bays have been frozen over so 



