88 



CRUISE OF STEAMER CORWIN IN THE ARCTIC OCEAN. 



with more southern points on the Alaskan coast, the foggy weather here is almost a minus 

 quantity. The misty rains occurring in summer so frequently take the place of fog,' and are 

 certainly no more agreeable. 



Tbe following exhibits the relative humidity for each month as averaged from the four years 

 preceding April 30, 1881 (the averaged observations are the 7 a. m., 2 p. m., and 9 a. m.) : Janu- 

 ary, 97.5; February, 98.5; March, 97.0; April, 96.1 ; May, 89.G ; June, 80.4; July, 82.1; August, 

 87.6; September, 89.0 ; October, 91.9 ; November, 92.4 ; December, 96.5. 



As would be expected, the relative humidity is greatest during the winter months and least 

 in summer. 



The lowest recorded humidity during this period was 37.4 on June 17, 1877, at the 5.24 p. m. 

 observation, the hygrometer 70°, and 56.50 for the dry and wet bulbs respectively. Iu spring, 

 during warm days in May and June, strange variations in the temperature and humidity fre- 

 quently occur. These are so pronounced that they are at once felt by any one standing outside at 

 the time, and appear to be cold waves laden with moisture and passing along with the wind. 

 These waves may pass in a few moments or may last an hour or over, and are followed by the 

 previous condition of the atmosphere, the contrast being sharply defined. 



The distribution of the annual precipitation is shown in the following table, which includes 

 the average monthly precipitation for the four years preceding April 30, 1881. Owing to tbe high 

 wind which so frequently accompanies rain or snow here, and in consequence renders a consider- 

 able rain or snow fall nearly immeasurable, Mr. Nelson has added, as nearly as possible, to this 

 series of figures an estimate of the error ensuing through tbis cause, and which he believes may 

 be reasonably placed at 50 per cent, of the measured, or 33£ per cent, of the total, precipitation. 



Month. 



January . . 

 February . 



March 



April 



May 



June 



July 



August ... 

 Sf|iti-inlHT 

 October . . . 

 November 

 December. 



Measured 

 amount. 



.54 



.05 

 .07 

 .34 



.87+ 



1.22+ 



1.65+ 



2.38 



2. 69+ 



.88+ 



.74+ 



.84+ 



Estimated cor- | 

 rection. 



Estimated 

 amount. 

 Total. 



.26 



.02+ 



.03 



.17 



.44- 



.61 



.83- 

 1.19 

 1. 35- 



.44 



.37 



.42 



.77 



.07 



.10 + 



.51 

 1.31 

 1.83+ 

 2.48 

 3.57 

 4.114 

 1. 32+ 

 1.11+ 

 1. 26- 



The average annual precipitation thus being as measured for the preceding four years, 12.24 

 inches, and plus the correction, which is undervalued if anything, equals 18.36 inches. As the 

 direction from which most of the rain or snow falls has been mentioned iu connection with the 

 winds, it is unnecessary to repeat it here. In but a single instance was a hard downpour of rain 

 witnessed, such as is common in lower latitudes, but either fine showers of short duration, or long, 

 steady, misty rains, which at times fall for a day or two, and scarcely produce a measurable 

 quantity of moisture in the gauge, though every exposed object becomes saturated like a water- 

 soaked sponge. The snow usually bears the same character, and falls iu flue, amorphous flakes, 

 rarely showing perfect crystalline forms, and as rarely falling in large flakes. During the summer 

 months, counting from the first of June to the end of September, there are a large proportion of 

 cloudy days, upon which no rain falls here, while many showers fall along the before-mentioned 

 range of coast hills. Some days not a drop of rain occurred here, though scarce ten minutes pass 

 during the entire day but a shower may be seen passing slowly along tbe line of hilltops some 8 

 to 12 miles away. In winter the same phenomenon is witnessed with snow showers. In both 

 cases the showers almost invariably traverse the hills from south to southwest to a northerly 

 direction, and leaving the hills, when the latter decrease rapidly in elevation to tbe eastward, the 

 showers pass on and are expended upon the sea. These showers are usually discharged from 

 more or less fairly-marked cumulus clouds, and may be frequently seen passing to the north or 

 northeast, while the wind at the place of observation may be in an exactly opposite direction, and 

 the clouds overhead present an unbroken and apparently motionless surface of dull gray stratus. 



