Remarks on the Barometer, &c. 345 
Arr. XIX.—Remarks on the Barometer, with a table of Meteoro- 
logical Observations, made on board of the U. S. Ship Peacock, 
from July 8th, to August 17th, 1837, during a passage From 
Peru to the United States, by way of Cape Horn, hi cto by 
W. S. W. Ruscuensercer, M. D., Surgeon U. S. Navy, &c. 
Tue barometer has not been in general use in the Navy of the 
United States more than fifteen or twenty years. Though this pe- 
riod is sufficient for establishing its utility in foretelling states of 
weather, it has not yet gained the universal confidence of the officers. 
However certain the indications of this instrument may be on shore, 
where it is at perfect rest, and where the observations may be made 
with the nicest accuracy, the same cannot be said of it when at sea; 
where, from the incessant motion of the ship, in spite of the best 
mechanical contrivance for its suspension, the mercurial column is 
constantly fluctuating, and therefore the observations are obnoxious to 
error, and at best must be considered only as proximative to the truth. 
In the British navy the same difference fe ‘pikade prevails, though 
we might infer, that it is implicitly relied on in some instances. We 
were told, when in China, that the commander of an English two- 
and-thirty gun frigate, in the month of August, 1835, actually threw 
overboard all his guns, because the rapid sinking of the barometer 
indicated an approaching typhoon. ‘This gentleman took to himself 
the credit of thereby saving the ship, which was in a few hours af- 
terwards thrown upon her beam ends by a violent storm, and with 
difficulty saved from total loss, even thus lightened of her battery. 
Such instances must go far in establishing” the claims of the instru- 
ment to confidence 
It is pretty gecietally conceded that the barometer is more faithful 
in its indications in some positions than in others; and while it is al- 
most altogether distrusted near the equator, it is confidetily referred 
to in high latitudes. In the city of Lima, Lat. 12° S, Dr. Unanue, 
(Observaciones sobre el clima de Lima,) tells us, the barometer only 
varies from two to four lines throughout the year, without any estab- 
lished order, the range being two lines higher in the summer than in 
the winter. It should be borne in mind, that the atmosphere of this 
region is rarely affected by any very strong commotion ; and in one 
instance, (April, 1808,) just before a fresh south gale, it rose between 
two and three lines above its ordinary maximum height. In the 
island of Ceylon, also near the equator, the barometer invariably 
foretells an approaching gale. 
