Appendix. I2g 



over 150 miles per hour. Assuming that the upper current, on 

 the 5th of February, had a velocity of half this, or 75 miles, it 

 would have taken about one hour for this mass of dust to have 

 been brought from Chicago. Or in other words, if it had been 

 taken up from this neighborhood, this would probably have been 

 done at about 3 P. M. As we have seen from the weather reports 

 quoted on the 5th of February, that the wind all through the 

 West and South-west was not a strong wind, and as it is hardly 

 probable that this great mass of matter could have been carried 

 up by anything but a strong wind, its elevation must have been 

 due to the powerful winds which were noted throughout the 

 West on the zd and 3d of February, if it was due to this cause. 



Being taken up into the upper atmosphere on that date, it 

 may have had its origin in the far south-western or southern part 

 of the United States, or in Mexico, where the surface of the 

 country was not covered with snow. 



Reports from this region as to the exact force of the wind 

 we have nqt been able to obtain. No tornado or cyclone of a 

 destructive nature is mentioned, however, in the papers of suc- 

 ceeding dates. In regard to the possibility of a volcanic origin, 

 the numerous cases recorded of a nature quite as impossible as 

 this, show that there are some grounds for the supposition of 

 such a theory. 



The incompleteness of reports which would furnish the 

 exact circumstances existing at various localities at the time of 

 the occurrence, and the very unfinished state of any investigation 

 into the case, would perhaps hardly warrant the adoption of any 

 decided theory. It is, to say the least, a strange phenomenon ; 

 and it being the only one to be found recorded as happening in 

 this State, at least, it is not without interest. 



