ing in N.-N.-W.; a continued roll of distant
thunder in the circular bank in N.-E., and not a moment's cessation to
the lightning; the electric excitement advancing westward along the
lines of cumuli; the cirrus haze also rising and passing towards S.-W.;
8 P.M., the sky alive with lightning, the cirrus now reaches the zenith;
no streaks of lightning coming to the earth; they seem to radiate from
the heaviest mass of cumuli, and spread slowly (sufficiently so to
follow them) in innumerable fibres over the cloudy cirrus portion of the
sky; every flash seems to originate in the same cloud; 8.30 P.M., one
branching flash covered the whole north-eastern half of the sky, no
leafless tree of the forest could show so many branches; 9.30 P.M., all
passed to S.-W. without rain, leaving behind a large cumulus, as if it
lagged behind. From this cumulus a straight line of lightning shot up
10d above the cloud into a perfectly clear sky, and terminated abruptly
without branching.

We have been thus particular in giving these details, as this was a
clear case confirming the principles advanced, that the vortices do not
form a continuous line of disturbance, in their daily passage around the
earth. It shows also that the barometer, in connection with these
principles, will be a far more useful instrument than it has yet proved
itself, for practical service as an indicator of the weather.

FOOTNOTES:

[10] For convenience to those wishing to verify the calculation of these
triangles, we have put down each side and angle as found. Also, as an
aid to the navigator.

[11] Daily Wisconsin, July 7.

[12] The author.

[13] Chicago Democrat.

[14] This was also calculated before the event.

[15] The letters in a parenthesis signify the direction of the wind.

[16] Giving this cloud the average velocity of thirty miles per hour,
its altitude was determined by the sextant at twelve miles, and we think
under-estimated. While measuring, the author's attention was drawn to
the fact, that although it appeared equally dense above and below, yet
its middle part was the brightest, and as there was only a faint glimmer
of twilight in the N.-W., he concluded that the cloud was self-luminous;
for when the smallest stars were visible, it glowed about as bright as
the milky-way in Sagittarius. Occasionally the whole cloud was lit up
internally by the lightning, and about this time it sent off three rays:
one horizontally, westward, which was t