78 O. N. Stoddard on the Brandon Tornado. 
9th. There was scarcely any hail, but torrents of rain followed 
the tornado, equally, and perhaps, more abundant outside of the 
track than within it. — 
10th. ‘The temperature sunk so rapidly that the next and suc- 
ceeding days became marked as among the coldest in the month. 
Rate of Progress. 
Great discrepancy existed between different observers in refer- 
ence to the progress of the storm. ‘The estimated time o its 
passage over any one place varied from one-half to one and a half 
2p. 
minutes. Mr. Coleman stated that he saw the whirling mass 
‘Minute as the time of its passage over any point, and three-fourths 
of a mile as the diameter of the storm, we obtain a velocity of 
45 miles per hour. 
I have not been able to obtain the barometric minima along 
the track of this extended S. West current; but if the lowest 
depression of the atmospheric wave passed near Little Rock, At- 
kansas, at noon on the 19th, then to have reached Oxford, Ohio, 
at 123 p.m. on the 20th, would have required a velocity of nearly 
29 miles per hour. My own opinion is that the first estimate is 
nearer the truth. The clouds during the forenoon of the 20th, 
flew past with a velocity which attracted special attention.* 
In reference to the velocity of rotation an approximate estimate 
only can be reached. If the ratio of the progressive and rotary 
velocities adopted in the construction of the cycloid be correct, 
and 40 miles per hour be taken as the rate of progress, then the 
velocity of the wind on the right would have been 120 miles pet 
hour. This velocity would be increased, especially near the axis, 
by the involute form of the curve; but to what extent this ope- 
rated cannot be stated. rig 
' Another mode of estimating the force of the wind may be 
adopted. Among the oaks previously named as standing on ris- 
ing ground, was one, a giant among giants. Its trank was three 
feet in diameter and straight; its top symmetrical, and the whole 
sound to the core. It was shivered to fragments near the ground. 
* Since writing the above, a communication from Mr. Raiff of Sandyville, north- 
eastern part of Tuscarawas Co., states, that the tornado peed about 1 mile south 
of that place at half past three o'clock v. w.; moving in a direction north of east, but 
grac 
from Sandyville, and passed on to the east; in all a course of 17 miles. Tht 
tion corresponds with what has already been stated. we < 
The roar of the tornado burst upon Brandon while the clock was striking 2 baie 
* ' an hour and @ 
uatly curving towards the east. It commenced southwesterly about 24 miles 
; The direc 
is corres 
ee eel with the previous estimate, the difference being only one-third fe 
ile. |The mode of action seems to have been the same; parts of buildings, itis — 
