DOI Page / Citation link:
https://doi.org/10.11588/diglit.20140#0192
168
geoup i., easteen india:
noted; the natives considered them to be connected with meteorological phenomena—"at
least," as they told me, "with the dissolving of fogs." The Europeans but too generally
think of atmospheric pressure being affected simultaneously; but the most careful
examination did not allow me to discover a connexion.
The details I shall give in the geological volume; here one result only, unexpected
for me, may be mentioned as being occasionally an assistance not indifferent for judging
of the connection with atmospheric changes, if any should exist—I mean the velocity
of the propagation of the shocks. In the alluvial soil forming the surface of the valley
of the Brahmaputra in its full breadth, from the Himalaya to the Khassia and ISTaga
mountains, with a granitic base below it and isolated granite hills, the propagation is
decidedly less rapid than that of sound. I had three times occasion1 to hear the horrifying
shouts from a village where a shock had been felt, before the shock reached my
encampment; a comparison of the distance and time gave about 1,000 to 1,005 feet
in one second, when I adopted Newton's value for sound = 1,140 feet in one second;
the temperature was 62° Eahr.
I may be allowed to add here that the observation of sound only allowed
of my estimating the propagation when my position was in the line of the propa-
gation, the waves coming towards me; in the direction at right angles to it, the neigh-
bouring places felt the shock simultaneously with me; in fact what I observed may
perhaps best be compared to a stream rushing forwards with a breadth not well
limited and with an intensity decidedly decreasing towards its lateral margins, but not
in its longitudinal direction.
The absolute extremes of temperature, given here are those communicated
for G-ohatti in Dr. Leslie's "Account of the Diseases at Gohatti."
The mean insolation is deduced from the observations made by myself and
my assistant Lt. Adams, together with Mr. Simons, 1855 to 1856; from October to
December it is decidedly more powerful than might be expected from the elevation
of the sun: atmospheric humidity in transparent state and the hibernal distance of
the sun materially increasing the effect of the sun's rays.
1 For details see Vol. VI., Geology.
2 As the value now best denned for the velocity of light, 41,549 geogr. miles (1 = >/16 degree = 4 nautical miles)
per second, is adopted. For details see Humboldt, "Kosmos," Vol. III., p. 92.
geoup i., easteen india:
noted; the natives considered them to be connected with meteorological phenomena—"at
least," as they told me, "with the dissolving of fogs." The Europeans but too generally
think of atmospheric pressure being affected simultaneously; but the most careful
examination did not allow me to discover a connexion.
The details I shall give in the geological volume; here one result only, unexpected
for me, may be mentioned as being occasionally an assistance not indifferent for judging
of the connection with atmospheric changes, if any should exist—I mean the velocity
of the propagation of the shocks. In the alluvial soil forming the surface of the valley
of the Brahmaputra in its full breadth, from the Himalaya to the Khassia and ISTaga
mountains, with a granitic base below it and isolated granite hills, the propagation is
decidedly less rapid than that of sound. I had three times occasion1 to hear the horrifying
shouts from a village where a shock had been felt, before the shock reached my
encampment; a comparison of the distance and time gave about 1,000 to 1,005 feet
in one second, when I adopted Newton's value for sound = 1,140 feet in one second;
the temperature was 62° Eahr.
I may be allowed to add here that the observation of sound only allowed
of my estimating the propagation when my position was in the line of the propa-
gation, the waves coming towards me; in the direction at right angles to it, the neigh-
bouring places felt the shock simultaneously with me; in fact what I observed may
perhaps best be compared to a stream rushing forwards with a breadth not well
limited and with an intensity decidedly decreasing towards its lateral margins, but not
in its longitudinal direction.
The absolute extremes of temperature, given here are those communicated
for G-ohatti in Dr. Leslie's "Account of the Diseases at Gohatti."
The mean insolation is deduced from the observations made by myself and
my assistant Lt. Adams, together with Mr. Simons, 1855 to 1856; from October to
December it is decidedly more powerful than might be expected from the elevation
of the sun: atmospheric humidity in transparent state and the hibernal distance of
the sun materially increasing the effect of the sun's rays.
1 For details see Vol. VI., Geology.
2 As the value now best denned for the velocity of light, 41,549 geogr. miles (1 = >/16 degree = 4 nautical miles)
per second, is adopted. For details see Humboldt, "Kosmos," Vol. III., p. 92.