/Miscellanies. 191 
The indeterminate use of the word collapse by persons attached 
to team boats, and by those who have given accounts of these acci- 
dents, has probably occasioned most of the misconception which 
appears to prevail on this subject. Most of the boilers which have 
failed in this vicinity, were so constructed as to contain large internal 
flues, which were broken in by the external pressure of the steam 
upon them, and the term collapse has been used merely to designate 
the direction in which the disruption has taken place, or rather toin- 
dicate the portion of the boiler which sustained the injury. 
To illustrate clearly the causes of failure in those boilers which 
have come under my own observation, would require a prolixity of 
detail which is not suited to the object of this communication. 
The statement of Professor Renwick, that in our American steam 
boats “there is never but one safety valve,” and that “ plates of fusi- 
ble metal are unknown,” is somewhat too broad, and is calculated to 
mislead the public, in regard to the actual state of what may be called 
practical science, in this country. Fusible metal was several years 
4g0 applied to boilers, as an additional means of safety, under the 
directions of the writer, and was also used in other boats navigating 
from this city. 
Although the strictest attention to the means of safety in steam 
boats cannot be too often or too strongly urged upon those who con- 
Struct or navigate them, still it is true that much unmerited censure 
has been dealt out to this class of persons, not only by the ordinary 
Periodical press, but sometimes through the medium of scientific 
Works of a more permanent character. It should always be recol- 
lected, that an undivided and careful attention to one or two safe- 
guards of known and acknowledged efficacy, will, in ordinary haads, 
7 da much greater degree of safety than can be secured by the 
adoption of all the contrivances with which curious or learned men 
«Ve from time to time become interested. A due regard to strength 
nthe form and structure of boilers, will remove all reasonable grounds 
of apprehension, in regard to a mode of travelling which is already the 
Salest, on the whole, of any with which we are acquainted. 
New York, September 24, 1831. 
an Hurricane of August, 1831.—In an article which was publish- 
ts 0 the April number of the American Journal of Science, I at- 
Mpted to show that storms and hurricanes consist in the regular 
S¥ratory motion or action of a progressive body of atmosphere 
