296 Tornado in N. E.part of Ohio, Feb. 4, 1842. 



observations. Those recorded in my former article range between 

 S. 54"^ W. ; South ; and S. 68° E. Near the centre were two 

 trees, S. 82° W., N. 86° W. These trees, it will be observed, 

 lie parallel with the track and almost directly in the centre. (See 

 this Journal, Vol. xlii, p. 12.) This southwest wind on the north 

 side of the track probably preceded the southeast, as the westerly 

 wind preceded the easterly on the south side. We may then pro- 

 ceed to construct a diagram of the wind's motions as at Mayfield. 

 The result is shown, Plate IV, Fig. 7. The motion is decidedly 

 centripetal, with a slight tendency to revolve with the sun. 



In order to obtain further light on the subject of tornadoes, I 

 have paid some attention to those small whirls which are not un- 

 common in warm days, which last but a few seconds, and elevate 

 light objects, such as leaves, dust, etc. March 31, 1838, about 

 llf A. M., I was walking alone in Hudson about half a mile 

 west of the college. My attention was attracted by a roaring 

 noise in a neighboring wood. I presently perceived a small whirl- 

 wind advancing into a cleared field, and marking its course by 

 dead leaves which were elevated into the air to the height of 

 pretty tall trees, and which revolved spirally upward in the direc- 

 tion of the sun's motion. The whirl advanced from S. 30° E. 

 to N. 30° W., which was the direction of the wind at that time 

 in this place, being somewhat of a ravine, although upon the hill 

 at the college soon after, the wind was northwest. I followed it 

 without any difficulty for several rods, until it came to a wood, 

 where its force was very much broken, and it soon disappeared. 

 I stood in the middle of the whirl and near its centre, and the 

 wind blew with such force that I was obliged to hold my hat on, 

 although the whirl advanced not more than three or four miles 

 per hour. It crossed a small brook about five feet wide quite 

 slowly, throwing up spray and a considerable quantity of water 

 about a foot high, and for a diameter about the same. It lasted 

 but a second or two, for the whirl passed nearly perpendicularly 

 across it. 



Aug. 22, 1838, 2 P. M. A whirl formed in the road directly 

 in front of the college. It moved a rod or two from north to south, 

 whirling in the direction of the sun. The motion was quite rapid, 

 and the whirl increased in dimensions from below upwards. Dec. 

 29, 1838, 10 A. M., a snow whirl revolved loith the sun. July 

 11, 1839, 10 A. M., a small sand whirl revolved in a direction 



