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DURATION OF THE AURORA.
319
the nigh/ of the northern hemisphere, that the auroras advance to a greater distance to the south, and appear to the inhabitants of the temperate
none. The periods during which these magnetic disturbances most frequently occur are those of the equinoxes, at the commencement and end
of the winter season. Meteoric phenomena of this kind are most scarce in
the month of June. M. Boue, who has made a list of all the scientific observations of auroras up to 1860, enumerates only seven for the month of
June, while no less than 458 have been recorded in March, and 498 in October at the time ofthe equinoxes. The figure on opposite page may give
January
October,
July
Pig. 146.—Monthly Distribution of the Aurora Borealis (after Klein).
some idea of the distribution of the auroras in the different months of the
year. Figure 146, constructed on slightly different data, and according to
a more logical method, as it represents the circle of the year, shows also
that this is the average distribution of these aerial storms.
It is probable, whatever the meteorologist GMsher may say, that the
magnetic auroras have also their periodicity, like all the other phenomena
of nature. This is established by the catalogue of observations made in
Europe and North America from the end of the seventeenth century to
our own time. In 1697 the auroras were not at all numerous, but they
| Title | The ocean, atmosphere, and life |
| Creator | Reclus, Elisée |
| Publisher | Harper |
| Place of Publication | New York |
| Date | 1873 |
| Language | eng |
| Type | Books/Pamphlets |
| Title | 00000350 |
| Type | Books/Pamphlets |
| Transcript | DURATION OF THE AURORA. 319 the nigh/ of the northern hemisphere, that the auroras advance to a greater distance to the south, and appear to the inhabitants of the temperate none. The periods during which these magnetic disturbances most frequently occur are those of the equinoxes, at the commencement and end of the winter season. Meteoric phenomena of this kind are most scarce in the month of June. M. Boue, who has made a list of all the scientific observations of auroras up to 1860, enumerates only seven for the month of June, while no less than 458 have been recorded in March, and 498 in October at the time ofthe equinoxes. The figure on opposite page may give January October, July Pig. 146.—Monthly Distribution of the Aurora Borealis (after Klein). some idea of the distribution of the auroras in the different months of the year. Figure 146, constructed on slightly different data, and according to a more logical method, as it represents the circle of the year, shows also that this is the average distribution of these aerial storms. It is probable, whatever the meteorologist GMsher may say, that the magnetic auroras have also their periodicity, like all the other phenomena of nature. This is established by the catalogue of observations made in Europe and North America from the end of the seventeenth century to our own time. In 1697 the auroras were not at all numerous, but they |
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