ijo ^Appendix. 



J. 



VARIOUS EXTRACTS FROM LETTERS REFERRING 

 TO THE ACTIVITY OF ICELANDIC VOLCANOES 

 ABOUT THE TIME OF THE COLORED SNOW- 

 FALL IN MICHIGAN. 



BY W. D. H E R D M A N. 



[Letter from Jon Olafsson to New York Times (?), written in Iceland, 

 June 16, 1875.] 



" Since the middle of December last year, people have 

 noticed many instances of earthquakes every now and then, es- 

 pecially in the eastern and northern part of the island. About 

 Christmas time, dense columns of smoke were seen issuing from 

 the mountains in the northeast, just east of the Odadwhraun, in 

 the so-called Dyngjufjoll or Askja, which is situated near the 

 65 north latitude and about 50' east of the Ferro-meridian. 

 After the middle of February, an outburst took place about *^ 

 north of the first one. There seems to be a line of volcanic 

 activity from Vatnajokull, and north as far at least as 655o' 

 north latitude, between the Jokulsa and Lake Mijvata. The 

 lava heaps, in some places, are about five miles long and half a 

 mile broad ; in other places again, as large as 14 miles long and 

 from 500 to 1,000 fathoms broad. Several visits have been 

 made to the fire, but none by scientific men. Are there no en- 

 terprising geologists in the United States who would be inter- 

 ested in visiting the places of the eruptions now, when they 

 seem to have ceased, at least for a time ? There has probably 

 never, in historical times, taken place anywhere on our globe 



