ARCTIC EXPLORATIONS. 295 



among our most eminent botanists as to whether the Arctic flora was 

 originally European or American. There is also an idea that at the 

 beginning of the last Glacial period the Arctic flora was driven south, 

 and, after the return of warmer times, followed the retreating ice, with 

 the exception of those species that were stranded and had taken refuge 

 on the mountain tops, the so-called Alpine flora. Further investiga- 

 tions in order to elucidate and solve these interesting botanical problems 

 would be of the greatest value. 



We have yet much to learn respecting the currents of air, the tem- 

 peratures, and other matters connected with meteorology wbicli, in all 

 probability, will be found, in a great measure, to affect the climate con- 

 ditions of lower latitudes. Further investigations in this particular 

 branch would doubtless result in the attainment of knowledge that 

 would be of great practical use and importance. 



What has been designated as the Greenland fohn is an atmospheric 

 condition prevailing at the same moment over different portions of the 

 Arctic regions situated at wide distances apart, and of which at pres- 

 ent little is known. At the Alert's winter quarters off the northeast 

 coast of Grinnell Land in 1875, we experienced great fluctuations of 

 temperature, varying no less than 55°; that is to say, that the ther- 

 mometer would make a sudden and rapid rise from —20° to +35°, and 

 sometimes this unusually high temperature, invariably accompanied by 

 a south wind, would last for a great many days, thus occasioning us 

 serious inconvenience from the unexpected warmth, for which we were 

 entirely unprepared. These warm southerly winds were felt on the 

 west coast of Greenland, between Ivigtut and Upernivik, precisely at 

 the same time that they were experienced by us, thus pointing to the 

 fact that the warm wave must have traveled at a prodigious rate, and 

 from a considerable distance, in order that it should have been felt, 

 practically, at the same time in places so widely separated. De Long 

 also remarks an unusual rise of temperature in the month of October, 

 when he was beset in the ice and drifting to the north of Herald Island, 

 and this increase of temperature was always accompanied by a south- 

 easterly wind. Immediately the wind veered round to tbe west, or 

 even to the southwest, the temperature promptly fell. 



This brings us to the equally important question of oceanology, which 

 should comprise a complete knowledge not only of the surface currents 

 in the Arctic seas, but also surface and deep-sea temperatures, forma- 

 tion, depth and nature of bottom, influence of tides, density of sea 

 water, varying conditions of ice, and other matters connected with the 

 hydrography of those regions. The strongest known currents that have 

 an outlet from the north polar basin are undoubtedly those that flow 

 to the southward down Eatflns Bay and Davis Strait and along the 

 east coast of Greenland. These are apparently uninfluenced by wind, 

 and their drift is both regular and rapid throughout the year. The 

 study of the system of these inflowing and outflowing currents is one 

 of great complexity but of vast importance. 



