MEMOIR OF AUGUSTE BRAVAIS. 153 



pears in tlie begiimiug of January and increases by degrees. Finally, on 

 the 31st of January, the solar disk begins again to show itself. It pro- 

 jects a first ray, which is hailed by the universal acclamations of the 

 population stationed at windows or on eminences to salute the benefi- 

 cent orb, whose priceless value is better felt after such an absence. On 

 that day all labor is suspended, felicitations are exchanged, dances ex- 

 ])ress the common joy, pledges are drunk to the resurrection of the sun; 

 it is the time also for settling the bets which have been made on the 

 rate of watches which, not having been regulated for two and a half 

 months, are liable to have become deranged. The sun, after this, rises 

 every day, at first for a few minutes only ; but the days gradually 

 lengthen; at the equinox thej^ are equal to the nights; then tlie nights 

 grow shorter, and finally extinct ; the sun ceases to set, and a continned 

 day of nearly three months forms the compensation for the long night 

 of winter. 



The perpetual day of the polar summer has never wanted witnesses ; 

 but it needed the resolution inspired by an ardent love of science to 

 await at Bossekop the festival of the resurrection of the sun. More 

 resolution still was needed to undertake the labors which the commis- 

 sion was charged with executing at that point. Xotwithstanduig the 

 relative moderation of the climate, the thermometer often descends at 

 Bosseko]), not, indeed, to 4:0 or 50 degrees centigrade below zero, as in 

 the north of Asia and America, but, according to the observations of 

 the commission, to 20^ or 25^ ; nor is the depression restricted, as in 

 our climates, to the last hours of the night. Here the night does not 

 terminate, and the diurnal variation of the temperature, evidently inde- 

 pendent of the action of the sun, the maximum occurring at 11 o'clock 

 in tlie morning and the minimum at o'clock in the evening, does not 

 exceed on a mean the tenth of a degree. The wind which at Bossekoi> 

 is least cold is that of the north, under the influence of the Northern 

 Ocean; while the coldest is that from the south, which bears the frozeL 

 air of the Scandinavian Alps. The temperature of the air is at its 

 minimum at the surface of the ground. It rises gradually by some de- 

 grees to a height of about one hundred metres, and afterward dimin- 

 ishes agreeably to the usual law. All the elements of the climate were 

 collected by our physicists through observations luade uninterruptedly 

 at intervals of two hours, and sometimes hourly, on the barometer, the 

 thermometer, the direction of the wind, the state of the sky, the tem- 

 perature of the earth at its surface, the magnetic apparatus, &c. All 

 these determinations, inscribed on registers kept constantly and with 

 perfect order, have been published in the great work of the Scientific 

 Commission of the North. 



The two marines and two professors divided between thein the labor 

 and the watching, the latter being observed with as much regnlarity as 

 on Itoard a man-of-war; but if an aurora borealis presented an extra- 

 ordinary brilliancy there was a general turnout; every one was at his 

 post. Some drops of coftee, seasonably taken, dispelled the importunate 

 somnolence of the Lapland night. Of the observers, while a jtortiou 

 noted every five minutes the positions assumed bj^ the magnetic needle 

 under the disturbing influence of the aurora, others, in the 'ipen air, 

 recorded, watch in hand, the diflerent phases of the phenomenon and 

 measured the altitudes above the horizon. The adjusting screws of 

 their instruments often became so cold that it was necessary to cover 

 them with cloth, without which precaution their fingers would have -id- 

 hered to the brass through the sudden congelation of the humidity of 

 the skin. 



