April 17, 1885.] 



SCIENCE. 



311 



been compiled from three }'ears' observations, 

 1875-76 and 1881-83. 



January 

 February 

 March . 

 April 

 May . . 

 June . . 

 July . . 

 August . 

 September 

 October . 

 November 

 December 



Tear . 



Barometer 



Tempera- 



to sea. 



ture. 



29.756 



-38.3° 



0.779 



-40.1° 



962 



-28.3° 



30.175 



-13.6° 



0.021 



+14.1° 



29.852 



32.7° 



0.725 



37.1° 



0.787 



33.8° 



0.749 



15.8° 



0.925 



- 8.9° 



0.971 



-23.3° 



0.830 



-28.1° 



29.878 



- 3.9° 



Rainfall, in- 

 ches (two 

 years only). 



0.42 

 0.13 

 0.45 

 0.17 

 0.40 

 0.18 

 0.66 

 0.38 

 0.35 

 0.24 

 0.20 

 0.30 



The barometrical observations show atmos- 

 pheric changes which I believe are common to 

 the region within the arctic circle, north of 

 America at least. The marked maximum 

 pressure in April gives way rapidly to the 

 principal minimum in July ; to be followed by 

 a secondary' maximum in November, and a less 

 marked minimum in January or February. 



The hourly barometric observations are of 

 special interest as tending towards a final solu- 

 tion of the question whether or not the regular 

 diurnal variation observed in lower latitudes 

 also occurs near the poles. Buchan, noting 

 the fact that the range at St. Petersburg and 

 Bosukop is but about .012 of an inch, remarks, 

 "And in still higher latitudes, at that period 

 of the 3 T ear when there is no alternation of day 

 and night, the diurnal variation probably does 

 not occur." 



The first year's observations at Fort Conger 

 satisfied me that such diurnal variation does 

 occur in very high latitudes, and my opinion 

 was confirmed by subsequent observations. 

 Reductions made several months before the 

 station was abandoned, from nearly five hundred 

 days' continuous observation, showed a range 

 of .0099 of an inch. The primary maximum 

 occurs at 5 a.m., Washington mean time (which 

 is 53 minutes slower than local time) , followed 

 by the primary minimum at 1 p.m. The second- 

 ary maximum and minimum took place at 6 

 p.m. and midnight respectively. To determine 

 whether the presence or absence of the sun 

 affected the fluctuation, I calculated separately 

 the means of the days of continual darkness 

 and continuous sunlight up to May 1, 1883. 

 The diurnal fluctuation was substantially the 

 same, and the critical hours were identical in 

 the arctic night and in the polar day. 



The absolute range of the barometer ob- 



served was 2.032 inches, — from 31, April 9, 

 1882, to 28.968, Feb. 19, 1883. It is interest- 

 ing to note that the minimum pressure for the 

 .year 1882-83 at Godthaab and in Spitzbergen 

 occurred respectively one da}^ earlier and three 

 days later than at Fort Conger. The barometer 

 at Godthaab touched the unusually low point 

 of 27.89. 



The annual mean temperature ( — 3.9°) is 

 the lowest on the globe, being 1.4° below that 

 deduced for Van Rensselaer harbor from Kane's 

 observations. It quite disposes of the theories 

 of a warmer climate as the pole is approached. 

 The maximum mean at Fort Conger agrees 

 with that of other arctic stations in general, 

 occurring in July ; and the monthly mean gradu- 

 ally declines to the minimum in February. 

 This month, I think, is generally the coldest at 

 arctic stations ; and, when the lowest mean has 

 been noted in January (or occasionally in 

 March), I believe a series of } T ears would 

 change it to February. The lowest monthly 

 mean ( — 46.5°) for February, 1882, must give 

 way, however, to that at Werchojansk (on the 

 Lena), from which the following means are 

 reported : December, —50.3° ; January, —56° ; 

 and February, — 53°. The highest monthly 

 mean was that of July, 1883, 37.2°. The ab- 

 solute range of temperature was 115.1°, — from 

 -62.1°, Feb. 3, 1882, to +53°, June 30, 

 1882. 



The amount of rain and melted snow was 

 3.95 inches the first, and 3.82 the second year, 

 irregularly distributed throughout the year. 

 This small amount of precipitation may ex- 

 plain the non-glaciation of the adjacent country. 

 I believe the precipitation in the interior to be 

 less than at Fort Conger. 



The wind resultants are as follows : first } T ear, 



S. 61.4° E. 7594 miles : second 



year, 



S. G7.3 C 



E. 6437 miles. The wind was more southerly 

 from 2 to 4 p.m., inclusive, than at other hours 

 during the first } T ear, and from 11 a.m. to 2 p.m. 

 the second } r ear. 



The mean tidal establishment was deter- 

 mined by me at Fort Conger from two years' 

 observations on a fixed gauge, as follows : — 



High water (1314 tides) . 

 Low water (1314 tides) . 



11 h. 33.9 m. 

 17 h. 45.7 m. 



Complete series of high and low waters for two 

 years, with regular hourly readings of the tide 

 for one year at Fort Conger, have been placed 

 in the hands of Mr. Schott. These observa- 

 tions, with supplementary simultaneous read- 

 ings at Capes Sumner, Beechy, Craj^croft, 

 Leebi, and at Repulse harbor, added to Bessel's 

 and Nares' observations, will, I trust, enable 



