s sometimes range
themselves, even by day, in a similar manner to the beams of the aurora,
and then disturb the course of the magnetic needle in the same manner as
the latter. On the morning after every distinct nocturnal aurora, the same
superimposed strata of clouds have still been observed that had previously
been luminous. The apparently converging polar zones (streaks of clouds in
the direction of the magnetic meridian), which constantly occupied my
attention during my journeys on the elevated plateaux of Mexico, and in
northern Asia, belong, probably, to the same group of diurnal phenomena."

Mr. William Stevenson gives us (in the London, Edinburgh, and Dublin
Philosophical Magazine for July, 1853) an interesting article on the
connection between aurora and clouds. His observations on this most
important branch of the subject trace a connection between the aurora and
the formation of cloud, and open up, as he says, "a most interesting field
for observation which promises to lead to very important results." Such
observations point with great significance, to the primary influence of
the magneto-electricity of the earth.

To the difference in the magnetic intensity of the eastern portion of this
continent, compared with Europe and our western coast, very much of the
difference of climate, so far as temperature is involved, may be
attributed. We have seen in what manner the iso-thermal lines surround
these areas of intensity. So the most excessive climate--that is, the
climate where the greatest extremes alternate, other things being equal,
is upon or near the line or area of greatest magnetic intensity. I say
other things being equal, because large bodies of water modify climates by
equalizing the seasons--making the summers cooler and the winters warmer
than the mean of the parallel.

Thus, our great interior lakes modify the climate in relation to
temperature in their vicinity. Their summers are cooler and their winters
warmer; but westward of them the same line of equal summer temperature, or
iso-thermal line, rises with considerable abruptness, and the winter, or
iso-cheimal line of equal temperature, falls in a similar manner. Thus,
the range of the thermometer, from the highest elevation to the lowest
depression, for the year, is very great, while in the tropics the range is
comparatively small. From observations made at the military posts of the
United States, Dr. Forrey deduced summer and winter lines of eq