barometer off Cape Horn was pointed out[1] as long as 1834. It was considered an anomaly peculiar to the regions of Cape Horn. It is now ascertained by the comparison of 6455 observations on the polar side of 40° south, and about 90,000 in all other latitudes, that the depression is not peculiar to the Cape Horn regions, but that it is general and alike in all parts of the austral seas, as the following table, compiled from the log-books of the Observatory by Lieutenants Warley and Young, shows:—
Barometric Table.
Mean Height of the Barometer as observed between
| the Parallels of | the Meridians of | Mean of all. | ||||||
| 20° W. and 140° E. | 140°E.and 80°W. | Of Cape Horn. | ||||||
| No. of obs. |
Barom. Inches |
No. of obs. |
Barom. Inches |
No. of obs. |
Barom. Inches |
No. of obs. |
Barom. Inches | |
| 40° S. and 43° S. | 1115 | 29.90 | 210 | 29.84 | 378 | 29.86 | 1703 | 29.88 |
| 43,,45 | 788 | .80 | 155 | .73 | 237 | .75 | 1130 | .78 |
| 45,,48 | 611 | .58 | 226 | .71 | 337 | .68 | 1174 | .63 |
| 48,,50 | 174 | .53 | 247 | .56 | 250 | .61 | 672 | .62 |
| 50,,53 | 108 | .35 | 198 | .45 | 359 | .56 | 665 | .48 |
| 53,,55 | 6 | .14 | 92 | .35 | 377 | .37 | 475 | .36 |
| 7 | .27 | 64 | .42 | 1055 | .28 | 1126 | .29 | |
671. Barometer at the poles.—These are the observed heights; for the want of data, no corrections have been applied to them; and for the want of numbers sufficient to give correct means, they lack that uniformity which larger numbers would doubtless give. They show, however, most satisfactorily, that a low barometer is not peculiar to Cape Horn regions alone; they show that it is common to all high southern latitudes ; and other observations (§ 362) show that it is peculiar to these and not to northern latitudes. Projecting on a diagram A, with parallels of latitude and the barometric scale as ordinates and abscissae, a curve S, which will best represent the observations (§ 670), and continuing it to the south pole—also projecting another curve N, which will best represent the observations (§ 362) on the polar side of 40° N., and continuing it to the north pole—we discover that if the barometric pressure in polar latitudes continue to decrease for
- ↑ American Journal of Science, vol. xxvi. p. 54 (1834).
