The New Orleans bulletin. [volume] (New Orleans [La.]) 1874-1876, 1875-09-14
GRADUATED ArMuSPHERES.

Mr. James McCarroll, of New York city, has
written very clever article on the subject of
! graduated atmospheres, which will attract
much attention. He says, among other
hings: For the sake of illustration, let us,
in imagination, project line perpendicular
, to the equator for distance of 20, 600 feet in
The direction of the midday sun; and let US
assume that this line is identical with the
course of single impulse sped through space
from that luminary to the earth, in relation to
which impulse, or ray of light if You will, the
angle of incidence and of reflection shall CO.
!ncide. Let US now, while the vertical sun
rests on the top Of this line, as it were, phi
Josephine upon some of the strata of atmos-
ohere through which it passes, always remem-
bering that the atmosphere is densest at the
level OF the sea, and that it becomes gradu-
,lly attenuated as we ascend through the re-
gions Of space.
Now, it has been ascertained, beyond
peradventure, that at the lower end of this
line man may be dying from the effects of
extreme heat the self-same moment that, at
the upper end, which is nearer the sun, an
other man may be dying from the effects of
extreme cold-the one being broiled and the
other being frozen to death. Nor is this all !;
for, midway between these two victims or at
height of nine or ten thousand feet, we find
a third persons enjoying himself in the open
air to the top of his bent. At no point OF the
sarth's surface are the regions, or, rather, the
extremes, OF heat and cold, defined so sharply
rs under the line. This is, doubtless, owing
the fact that the angle of incidence, and
hat of reflection, are coincident on the part
Of the solar beams.
As we re cede from the equator this angle
becomes greater and greater, with correspond
ng diminution of light and heat, until we reach
he poles, where it falls into one horizonta
lime, as it were. And perhaps this gradual dim
mutton Of light and heat is not so much owing
to the alleged fact that as we recede from the
inc any given number of rays of light are
made to cover a greater space. as to the OBJ
Ivious one that the angle of incidence and that
|)f re Il ection become more obtuse at each sue
|,essive STEP Pencils of what we call light
IRE of infnitesimal proportions. Let us, then,
project one of the smallest within the COM
pass of an experiment upon q rejecting sur
face in. dark room, and perhaps we
shall be able to discover that the secondary
ray performs more important mission in the
concentration of light and heat than is usually
accredited to it; for it is obvious that, the
smaller the angle here, the more light and
heat are expressed within it; while it appears
10 be equally true, also, that the gradual
shading off of climate, from intense heat to
intense cold between the equator and the
poles, is owing, perhaps, more clearly to the
Gradual augmentation Of this combined angle
than to any other circumstance. Still, at any
intervening point, the vertical admeasure-
.ment, through the atmosphere, holds relative
lily good-that is, the more attenuated any of
the strata, the colder and, doubtless, the
arker it Is.
From these few speculations, it may Dos
|sbly appear to some that the nearness of
planet to the i, or the remoteness of one
from that mighty orb, has not, after all, SO
much to do with the degree of light and heat
experienced by these bodies. Graduated at
|nospheres, from Mercury to Neptune, would
seem to secure something like an equal distrib-
ltion of light and heat among all the members
of our system. highly attenuated atmos-
,here for Mercury, and one CORRESPONDENCE
tense for Neptune, would place both these
planets in more comfortable position, in our
imagination, than they have occupied hereto
tore.