882, at 10:30 A.M., so great that he
could hear persons upon the opposite side of the street, but could not
see them--"It was obvious that there was no fog to speak of."

_Annual Register_, 1857-132:

An account by Charles A. Murray, British Envoy to Persia, of a darkness
of May 20, 1857, that came upon Bagdad--"a darkness more intense than
ordinary midnight, when neither stars nor moon are visible...." "After a
short time the black darkness was succeeded by a red, lurid gloom, such
as I never saw in any part of the world."

"Panic seized the whole city."

"A dense volume of red sand fell."

This matter of sand falling seems to suggest conventional explanation
enough, or that a simoon, heavily charged with terrestrial sand, had
obscured the sun, but Mr. Murray, who says that he had had experience
with simoons, gives his opinion that "it cannot have been a simoon."

It is our comprehensiveness now, or this matter of concomitants of
darknesses that we are going to capitalize. It is all very complicated
and tremendous, and our own treatment can be but impressionistic, but a
few of the rudiments of Advanced Seismology we shall now take up--or the
four principal phenomena of another world's close approach to this
world.

If a large substantial mass, or super-construction, should enter
this earth's atmosphere, it is our acceptance that it would
sometimes--depending upon velocity--appear luminous or look like a
cloud, or like a cloud with a luminous nucleus. Later we shall have an
expression upon luminosity--different from the luminosity of
incandescence--that comes upon objects falling from the sky, or entering
this earth's atmosphere. Now our expression is that worlds have often
come close to this earth, and that smaller objects--size of a haystack
or size of several dozen skyscrapers lumped, have often hurtled through
this earth's atmosphere, and have been mistaken for clouds, because they
were enveloped in clouds--

Or that around something coming from the intense cold of inter-planetary
space--that is of some regions: our own suspicion is that other regions
are tropical--the moisture of this earth's atmosphere would condense
into a cloud-like appearance around it. In _Nature_, 20-121, there is an
account by Mr. S.W. Clifton, Collector of Customs, at Freemantle,
Western Australia, sent to the Melbourne Observatory--a clear
day--appearance of a small black cloud, moving not very
swiftly--bursting into a ball of fi