1874.] The Iowa and Illinois Tornado. 345 
running east and west, trees were lying just as they fell, 
some pointing east and some west. 
One quarter of a mile beyond Mrs. Dogget’s house the 
tornado reached North Skunk river, which it then followed 
for over 2 miles, in a south-easterly direction, until it came 
to the southerly bend of the river, opposite Kohlhaus’s 
saw-mill, when it suddenly turned to the north-east. The 
bottom lands on both sides of the river are here covered 
with tall timber, and through this timber the storm tore its 
way with resistless fury. All trees within a breadth of about 
roo yards were either overturned or broken off and barked. 
The barking was evidently the result of three things :— 
1. Many of the trees barked had been bent, so as to loosen 
the fibres of the wood. Such bending would infallibly 
loosen, and perhaps break, the bark. 
2. The air was thick with missiles, which not only broke 
the bark, but sometimes penetrated the wood. I have 
seen a corn stump less than 2 inches in length 
sticking in the bark of a large tree which it had 
penetrated. 
3. The peeling off of such loosened and broken bark 
would be a light task for such a tremendous blast. 
There was not the slightest evidence of electric action 
or of vapour explosion. 
Broken trees had the bark torn off, both up and down, 
from the point of breakage. Trees half broken and bent to 
the ground were similarly stripped. 
At the place of rupture the trees generally presented that 
broom appearance in which the supporters of the theory 
that electricity is the principal agent in the production of 
tornadoes have seen conclusive evidence of its truth. It 
will afterwards be shown, when this phenomenon becomes 
more common than could be expe¢ted on the soft soil bor- 
dering North Skunk river, where trees were more easily 
uprooted than broken, that this broom appearance is due to 
the excessive bending and straining of the fibres of the 
wood, and their rupture, in succession, from the exterior 
inwards. 
The river, being impassable, rendered the examination of 
the general position of the fallen trees more difficult. 
Everything, however, corroborated the evidence already so 
abundantly adduced, that the tornado was a whirlwind of 
powerful centripetal tendency, circling contrary to the hands 
of awatch. The following arrangement of fallen trees was 
selected as being typical. It was found on the north side of 
the river, near the centre of the tornado. 
