On the Evidence of Certain Phenomena, &c. 315 
in mid-ocean, in the Indian seas, and on the bosom of the great Pa- 
cific. But to return to the only remaining position which is called 
in question by the author of the notes, and which is in the following 
words. 
“The regular semidiurnal variations of ‘“ barometer is at its maximum 
about 10, A. M., and at its minimum about 3, P. M.; at New York it is nearly 
the same ; but at Edinburgh, the effect is cemented. the minimum being at 10, and 
happened on the following passage in ee mane report of the British As- 
Seniation forthe Advancement of Science, p. 
This is followed by a condensed statement of the observations 
made near Edinburgh, by Professor Forbes, since 1827, which have 
been published at length in the Edinburgh transactions ; from which 
it appears that near Edinburgh, in latitude 56°, the mean annual 
oscillation between 10, A. M. and 4, P. M., is .0106 inches; and 
that the St. Bernard observations, 8000 feet above the level of the 
sea, and those of Capt. Parry, in the Arctic regions, both indicate a 
true negative oscillation, &c. 
I readily acknowledge a partial inaccuracy in my statement, which 
should have read, ‘‘but in high latitudes the effect is reversed,” &c. 
the locality or latitude of Edinburgh not being that in which the 
negative oscillation is established; and the error was subsequently 
so corrected. Itmay, however, be proper on this occasion to explain 
the cause of the inaccuracy. A short time before I was called upon 
to sketch the facts in meteorology, to which the foregoing exceptions 
bave been made, the paper of Professor Forbes, above referred to, 
had met my eye, under circumstances, however, which precluded its 
perusal; bat in glancing over its pages, and the illustrations which 
accompanied it, I perceived that the Professor had shown a negative 
oscillation of the barometer, taking effect somewhere in the higher 
latitudes, and his extensive series of observations having been made 
near Edinburgh, I was led to infer that this conclusion, or result, 
had been directly deduced from these observations. Under this 
impression, I ventured to pen the statement in its original form, 
which { should not have done, however, unless I had at that time 
felt myself certain of an opportunity to give the paper of Professor 
Forbes a thorough perusal, before my statement should pass through 
the press; but the concurrence of an unlooked-for accident, with a 
more speedy publication than I had anticipated, prevented my de- 
sign from being realized. 
