On the Causes of the Tornado, or Water Spout. 153 
in the Monoclinate system of crystallization, (his Zwei- und einglied- 
riges Krystallisation-system,) and retains the Tantalite only in the 
Trimetric system, (his ein- und einaxiges Krystallisation-system. ) 
Mr. Rose however remarks, that the ate specimen he has observed 
which leads to this conclusion, was a large crystal in the Berlin Mu- 
seum, with faces too uneven to admit of measurement, and concludes 
by observing that other examinations would be required, to establish 
the certainty of the above conclusions. This subject, therefore, still 
remains in doubt, and can be cleared up only by accurate crystallo- 
graphic examinations. The Tantalite from Finland afforded Ber- 
zelius, Columbic acid 83.2, Protoxyd of iron 7.2, Protoxyd of man- 
ganese 7.4, Oxyd of tin 0.6=98.4. 
Arr. XV.—On the Causes of the Tornado, or Water Spout; by 
R. Hane, M.D. &c. &c 
In July last, I visited the scene of the tornado, which had in the 
previous month produced so much damage in and near New Bruns- 
wick, New Jersey, and heard it deskribed by various witnesses, and 
have likewise been edified by the observations made respecting its 
effects by Professors Henry, Torrey, Johnson, and other sagacious 
and learned observers, and especially those of my friends, Prof. A. 
D. Bache and Mr. Espy. Probably in no other instance have the 
effects of a tornado been so faithfully and skillfully traced, ascer- 
tained and registered. Prof. Bache regularly surveyed the path of 
the devastating agent, and ascertained the bearings of the various’ 
bodies prostrated by it, so as to make several accurate plots. From 
an examination of these, the proximate causes of the changes effect- 
ed, are those of a vertical current at the centre or axis of the tor- 
nado, aud of a horizontal conflux of the air towards that axis from 
the surrounding space. Some trees appear to have been thrown 
down on the approach of the hiatus, both directly in front of it and 
on either side ; some fell at right angles, others obliquely to the path. 
Hence they were found to have a great variety of bearings, but al- 
ways pointing towards the path, ‘The time of their falling, and con- 
sequently the direction agreeably to the observations of Prof. Bache, 
appear to have been determined not only by the extent of the force 
to which they were exposed, but likewise by the strength of their 
os or the degree of protection afforded them by other bodies, 
XXII.—No. 1. 2 
