42 Prof. Loomis on the Hail Storm of the first of July, 1853. 
(the first Presbyterian Church) I noticed a phenomenon which I 
considered worth recording. ‘The track crossed the ridge of the 
church at an angle of about 45°. On the leeward side, the tin 
roof was started from the boards (but not broken) and pufied up 
forming a wrinkle about twenty feet long, two or three feet wide, 
and ten inches high. ‘This appears to me to indicate the opera- 
tion of a force beneath, pushing up the tin ; but not being able to 
tear the tin open, bulged it up and left it in a ridge. 
This phenomenon appears to be analogous to what often occurs 
in tornadoes, and I ascribe it to a rarefaction of the air on the lee- 
r 
windward roof remains. In the present case, this upward pres 
sure lifted the tin about ten inches, stretching but not tearing it 
This force appeared to be insufficient to tear the tin from its fasten- 
ings—perhaps because from the carrying away of the steeple, and — 
the ripping up of the adjacent edge of the tin, the air beneath © 
found a ready escape. 
In the neighborhood of the Crystal Palace, occurred a phenom- 
enon which appeared to indicate the existence of currents blow- 
ing nearly in opposite directions. ‘The wooden buildings, which — 
have already been mentioned, were blown toward the southeast — 
—but the brick wall, the line of which run from N. 28° E. to — 
S. 28° W., fell toward the west; that is, in a direction neatly 
contrary to that of the storm’s progress. 
e following appears to me to be the explanation of this 
phenomenon. ‘The Latting Observatory is an octagonal tower; 
300 feet high and 75 in diameter at base, sloping uniformly — 
to the top. In the annexed figure, 
the octagon represents the base of the 
tower, and the line NS represents a4 
meridian. On the west side of the 
tower, was erected a brick wall A B, 
25 feet high, and only three feet from 
the side of the tower. At the south 
end, it was connected with another 
wall B H, but at the north end it was 
BE 
the storm’s progress is indicated by the. = 
arrow. Itmight have been anticipated that the wall A B would — 
have been thrown towards the east upon the tower; whereas i 
fact it was thrown outwards towards the west. But we knoW 
