36 



CONTRIBUTIONS TO THE NATURAL HISTORY OF ALASKA. 



The second class will embrace all other kinds, with their variableness of intensity and form. 

 Rarely an arch forms itself unless preceded by the first class as a haze. 



This second class to be produced, the haze gathers into a pale narrow arch of variable height, 

 usually at 20 degrees altitude, increases in brightness by 9 o'clock, and then forms a second arch 

 above, at a distance varying from 5 to 20 degrees, and rarely more than 6 to 10 degrees wide. 

 Three or more arches are rare. The single-arched variety has its eastern and western ends 

 incurved at times. Also the eastern end is often broken into a sheet, or patches irregularly 

 scattered, but in the maximum intensity they are absorbed into the arch. Beams, waves, stream- 

 ers, folds, and other fantastic perturbations attend a brilliant display. These beams move east 

 to west, or vice versa, on the arch with a frightful velocity. Sometimes beams move from east to 

 west while others from west to east are being translated with the same rapidity. 



No clash or interference is observable. These pulsations sometimes travel the entire length 

 of the visible length of the arch in less than two minutes, and once in less than one minute. The 

 highest grades of auroras seldom occur over this locality. The corona has been but Quce perfectly 

 developed. The width of beams, arches, &c, are variable, as is also the length of the streamers. 

 The usual color is pale straw to sulphur-yellow. Other colors have never but twice been observed. 

 Recurring fits are but differences of intensity, and may be said to attend all the displays excepting 

 those of the first class. The dark segment, when present, is usually sharply defined. 



The frequency of auroras at this station is somewhat less than is assumed for the latitude of 

 64 degrees north, and is probably due to the prevalence of clouds during the months of greatest 

 frequency. For four months, May, June, July, August, and a part of September, auroras are not 

 observable at all from the twilight. March and February show the greatest number of displays, 

 and for the entire year about thirty-two auroras are recorded. 



Summary of meteorological observations taken at Saint Michael's, Alaska. 



Date. 



1874. 



July 



August 



September 

 Ootober 



November . 

 December . 



1875. 



January ... 

 February . . 



March 



April 



May 



June 



July 



August 



September 



October 



November . 

 December . 



1876. 



January ... 

 February . - 



March 



Apiil 



May 



June 



July 



August 



September . 



October 



November . 

 December . 



29. 902 

 29. 964 

 29. 764 

 29. 639 

 29. 775 

 29. 583 



30. 029 

 29. 753 

 29. 954 

 30. 117 

 29. 694 

 29. 815 

 29. 925 

 29. 717 

 29. 719 

 29. 694 

 30. 281 

 29. 966 



29. 814 



30. 207 

 3(1. 145 

 29. 899 



1877. 



January . . 

 February . 



March 



April 



May 



June 



29. 763 

 29. 808 

 29. 825 

 29. 675 

 29. 665 

 30. 145 

 29. 749 



29. 908 

 30. 103 

 29. 880 

 29. 704 

 29. 584 

 29. 821 



s ® 



30. 281 

 30. 435 

 30. 101 

 30. 311 

 30. 852 

 30. 580 



30. 799 

 30. 264 

 30. 703 

 30. 645 

 30. 289 

 30. 368 

 30. 312 

 30.112 

 30. 289 

 30. 583 

 30. 998 

 30. 463 



30. 582 

 30. 689 

 30. 598 

 30. 366 



30. 009 

 30. 295 

 30. 150 

 30. 285 

 30. 323 

 30. 632 

 30. 494 



30. 427 

 30. 625 

 30. 179 

 30. 145 



29. 992 



30. 305 



So 



29. 426 

 29. 375 

 29. 332 

 29. 026 

 29. 085 

 29. 015 



28. 875 



29. 269 

 29. 058 

 29. 481 

 29. 277 

 29. 382 

 29. 645 

 29. 301 

 29. 4U4 



28. 862 



29. 399 

 29.011 



29.018 

 29. 341 

 29. 358 

 29. 335 



29. 419 

 29.219 

 29. 196 

 28. 700 



28. 722 



29. 495 

 28. 941 



29. 211 

 29. 371 

 29. 290 

 29. 022 

 29. 078 

 29. 456 



P. 



a . 



52.7 

 53.0 

 42.9 

 28.4 

 20.3 

 16.9 



17.1 

 20.4 



6 

 12.4 

 30.5 

 44.8 

 55.4 

 50.7 

 45.5 

 35.4 



8.0 

 —0.7 



P< 

 S 



a* 



8.9 



34 



-9.3 



17 



7.05 



34 



15.7 



41 



37.4 



57 



47.4 



75 



52.7 



68 



49.2 



64 



44.4 



59 



30.3 



43 



6.9 



36 



3.4 



36 



1.6 



41 



-23.8 



12 



12.7 



38 



28.8 



43 



37.4 



57 



52.2 



70 



38 

 39 

 23 

 13 

 1 



-37 



-25 



-36 



-23 



15 



29 



39 



28 



30 



17 



-17 



-32 



-28 



-40 



-28. 



—17 



16 



32 



39 



34 



31 



8 



-24 



-25 



-39 

 -50 

 -16 

 - 3 

 16 

 36 



-SI* 



<* 2 

 h a 



2"= 

 3 S 

 *4 a 



1.18 

 2.07 

 0.79 

 2.06 

 0.78 

 2.03 



0.28 

 0.09 

 <*) 

 '0.03 

 0.31 

 0.67 

 1.45 

 2.21 

 2.00 

 0.22 

 0.20 

 0.57 



0.33 

 (*) 

 C) 

 1.58 

 *0.41 

 1.46 

 1.81 

 3.13 

 3.24 

 1.67 

 0.33 

 0.10 



0.93 

 (*) 



0.27 

 0.42 

 0.39 

 1.08 



>■■•% 



C3 g 



12 



18 



16 39 



22 23 i 87 



11 57 ! 70 



24 j 20 j 74 



15 14 105 



15 2 146 



16 



27 I 15 



23 10 



1 2 



27 ! 1 



13 ! 9 



14 ; 37 



27 . 22 

 6 6 



14 37 



15 18 



15 



21 12 



15 ! 16 



8 I 4 



25 



1 



12 



17 

 40 



■fa 

 > o 



2a 



9,675 

 9,005 

 9,491 

 U, 838 

 12, 264 

 14, 182 



15, 798 

 16,344 

 18,416 

 11,991 

 13, 797 



13, 397 



14, 433 

 14, 827 

 12, 503 



16, 511 

 7,950 

 9,568 



16, 298 

 7,156 



11, 396 

 8,477 



13, 020 

 8,779 

 7,560 



17, 112 

 6,480 



18, 720 



14, 036 

 4,680 

 6,696 

 12, 456 

 16, 368 

 12, 831 



2 

 4 

 10 

 3 

 

 

 

 



1 



5 



7 



12 



2 

 11 

 7 

 3 

 

 



Snow drifted too much to allow accurate measurements. 



