346 Remarks on the Barometer, &c. 
At places beyond the ‘tropics, scarcely a difference of opinion ex- 
ists on the subject. At Valparaiso, Lat. 33° S., any considerable 
fall of the mercury is almost always followed by a gale from the 
north, accompanied by heavy rain; and at the Cape of Good Hope, 
Lat. 35° S., the sinking of the barometer always precedes the 
storm. Off Cape Horn, Captain King, R. N., found its indications 
of the utmost value, and states that its variations “correspond to 
those of high northern latitudes in a remarkable manner, chang- 
ing south for north, east and west remaining the same.” In anoth- 
er place he says, ‘‘with respect to the utility of the barometer 
as an indicator of the weather that is experienced off Cape Horn, I 
do not think it can be considered so unfailing a guide as it is in the 
lower or middle latitudes. Captain Fitz Roy, however, has a better 
opinion of the indications shown by this valuable instrument: my 
opinion is, that although the rise or fall precedes the change, yet it 
more frequently accompanies it.”* 
- The barometer is subject to a diurnal flux and reflux, which was 
first remarked, I believe, by Baron Humboldt, in 1802, at Lima, and 
since confirmed by various observers at other places. At that place, 
Dr. Unanue states, it rises from five o’clock, A. M. until nine, the 
time of its maximum height; from that hour until meridian, it re- 
mains Stationary ; ; then falls until four o’clock, P. M. and remains sta- 
tionary ; it again rises from seven till eleven o’clock, and again de- 
scends from midnight until four o’clock, A. M. 
The variations of the barometer were noted every four hours, 
through the day and night, in a range of 93 degrees of latitude in the 
Auantic, and 45 degrees in the Pacific ocean. 
The first column in the table shows the day upon which the obser- 
vations were made; the second, the position of the ship ; the third, 
the hour of the day, beginning at the meridian, (marked m,) the fig- 
ures 4 and 8, immediately following, are four and eight o’clock, P. 
M.; 0, is the sign of midnight, and the figures 4 and 8 are four and 
eight o’clock, A. M.; so that the divisions of the day are in accord- 
ance with the nautical method of reckoning time. The fourth col- 
umn contains the variations of the barometer; the fifth and sixth, 
the temperature of the air and water by Fahrenheit’s thermometer ; 
the seventh, the direction of the wind ; the eighth, the distance run 
by log each four hours, to show proximately the force of the wind, 
* Sailing Directions for the coasts of eastern and western Patagonia, &c., by 
Philip Parker King, Captain R. N., F.R.S., &c. London: 1832. 
