s average
height, in England, is 29.94 inches (at 32 deg.).

[12] In an Aneroid, a metallic, or a wheel barometer, the hand's motion
should correspond to that of mercury in an independent instrument.

[13] Southerly in South latitude.

[14] In the best columns, those of standards for example, no concavity
is seen, at any time: but it is otherwise with many barometers, which do
show a concavity.

[15] In these cases there is usually a combination or a contest of
currents in the atmosphere, horizontally, _or_ one _above_ the other, or
diagonally.

[16] Thunder clouds sometimes rise and spread against the wind
(lower-current). It is probable that there is a meeting, if not a
contest of air currents, electrically different, whenever lightning is
seen. Their concurrence, when the new one advances from _polar_ regions,
does not depress the barometer, except in oscillations of the mercury,
which are very remarkable at some such times.

[17] Aneroids, metallic barometers, and oil sympiesometers, seem to be
much more affected than mercurial barometers by electrical changes.

[18] Southerly, in North latitude; the reverse in the Southern
hemisphere.

[19] A "high dawn" is when the first indications of daylight are seen
above a bank of clouds. A "low dawn" is when the day breaks on or near
the horizon. The first streaks of light being very low.

[20] Indications of weather, afforded by colours, seem to deserve more
critical study than has been often given to the subject. Why a rosy hue
at sunset, or a grey neutral tint at that time, should presage the
reverse or their indications at sunrise;--why bright yellow should
foretell wind at either time, and pale yellow, wet;--why clouds seem
soft, like water colour; or hard edged, like oil paint, or Indian ink on
an oily plate;--and why such appearances are infallible signs--are yet
to be shown satisfactorily to practical men.

[21] In the trade winds of the tropics there is usually a counter
current of air, with light clouds,--which does not indicate any
approaching change. In middle latitudes such upper currents are not so
evident, except before a change of weather.

[22] _Much_ refraction is a sign of Easterly wind. _Remarkable_
clearness is a bad sign.

[23] The "young moon with the old moon in her arms" (Burns, Herschel,
and others) is a sign of bad weather in the temperate zones or middle
latitudes, because (probably) the air is then exceedingly clear and
transparen