174 THE TORNADO OF 1851. 



before the survey was commenced, and as it was considered important that some trace 

 of these trees should be preserved, though the direction of their fall could not be given, 

 a symbol was adopted to designate them. 



Some persons entertain the belief that the more fragile substances, as corn and grain, 

 give the best indication of the direction of a storm, and this the more especially, because 

 they attach great importance to the evidences of reaction, after the immediate violence 

 of the storm has passed. It is not from inadvertency that no trace is left, among the 

 results of the survey, of any observations upon this point. Several cornfields were passed 

 on the route, and each one was made an object of special study and observation. Un- 

 fortunately, the time which had elapsed since the occurrence of the storm rendered these 

 observations useless. A farmer with whom I conversed described his cornfield as pre- 

 senting, on the morning after the storm, the appearance of a field over which a heavy 

 roller had passed, — the stalks all bent down in one direction. But for the several suc- 

 ceeding days strong northerly winds prevailed, and the consequence was, that, at the 

 time of my observations, some of the stalks were straightened up again, others bent 

 back, and the whole scattered to every point of the compass, so that I was unwilling to 

 record a solitary observation as reliable. 



So far as the reaction is concerned, I have no hesitation in saying, that many of the 

 exceptional cases to be found on the map are to be explained by it alone, and too much 

 caution cannot be exercised in basing any theory upon a few cases of anomalous action. 

 A mere glance at the map will show that, throughout the whole track, the trees generally 

 point inwards, towards the axis, so that at almost any point a person may put his finger 

 upon the axis line. I believe that this indication is so reliable, that I had at one time 

 intended to mark an axis line in each of the sections of a hundred feet, by this indi- 

 cation alone, and then, by connecting all these, to give upon the map the true axis of 

 the storm, that it might be shown at the same time whether it was straight or curved, 

 and if curved, how great was its curvature. But I finally determined to leave this to be 

 done by those who might study the map, and preferred to hold to my first resolution, to 

 put down nothing which did not present itself on the actual survey, and thus leave 

 every thing open to the theories of others. 



But while this first conclusion is very apparent, a more minute inspection will show, 

 that even where the general indications are most distinctly marked, in other words, where 

 the trees do with very great uniformity dip towards the axis, — those in its immediate 

 vicinity coinciding with it in direction, and as we remove from it on either side making 

 a greater angle, increasing with the distance from the axis, until at the outermost verge 

 the angle reaches nearly 90^, — at these very places we may find some trees dip- 



