The sun. [volume] (New York [N.Y.]) 1833-1916, 1891-08-16

surface. II IL consequently but the remnant
OF q great crater ring. Even in that condi-
ton, however, IL would be visible to the eye,
but for the fact that its hugo nsighbor.
Copernicus, whose walls are stu staining
to a great height. is surrounded by enor-
nous masses Of luminous material, which
looks like lava that must have overlooked
tho surrounding country ages ago, and
reflects back the light OF the sun to our eyes
with overpowerinR briTllancy. The glare OF
this broad rejecting surfnce, covering hun
dreds OF square miles, Is 30 great "a to
conceal the comparatively low relief Of the
broken crater ring.
In fact, It IL not improbable that Coperni-
Gus is responsible for the disappearance of
the other grent crater, which doubtless was
the predecessor Of Copernicus. and once
lowered up to on equal height above the
surrounding plains. After It had ceased to
be an nctive volcano, and Copernicus had
burst forth, tho lntter probably overwhelmed
II with torrents OF lave, which, filling up tho
space within Its broken walls nearly To tho
level VI their tops, submerged II, so to spenk,
beneath the new surface thus formed. so
thnt only tho summit Of It's bt oxen walls re-
mains TO he caught by tho acute vision Of
the Photographic plate.
In other parts OF tho moon similar events
appear TO have taken place, and there are q
number Of large craters, enormously greater
than any volcanic crnters upon the earth.
which seem to have been buried by the ont
burst Of lava from subsequently formed vol
cano's In thoir nelghborhood. 80 that only
portions of their mountain walls now re-
n,rin visible.
Another discovery, also arising from In
spcction of the negatives made With tho
LICK telescope, relates ~ tho wonderful aye
tom Of bright rnys surrounding the most
perfect crater IN the moon, Tycho. This
extinct volcano IL como fifty-ionr miles In
diameter, and Is surrounded on the outer
eide Of It's lofty walls by 4 comparatively
level region, Sonic twenty-five miles broad,
Of q much darker hue than that " the
crater itsc!f or Of the surrounding country
beyond. The hundreds OF great streaks
which radiate from Tycho like the epokes OF
. wheel. varying In width from ten 70
twenty or thirty miles, and In length from
Q few miles 70 nearly 2Oo0 miles, have
always appeared, when viewed with a
telescope alone. to take their rise from tho
outer edgo OF the dark rim surrounding
tho crater but the LICK negatives show
that some OF the strraks at least
pass through this dark rim and extend
cleur MP TO the very walls Of the crater Tho
suggestion that these mysterious streaks
had their origin in tho volcanic energy II
Tycho when 1t was still On active crater. is
strengthened by this evidence that the
streaks actually reach to the crater itself.
These discoveries are likely to give re-
newed interest to the study Of tho moons
surface. and while It is perhaps too much
to expect that . great deal OF light will be
thrown by astronomical photography upon
the question whether evidences OF the pres
ent or former existence OF life upon tho
moon can be detected from the earth. yet
there can be no question that new method
Of attacking the many problems that still
remain to Be solved concerning the charac-
ter and condition Of our satellite has BEEN
placed within the teach Of astronomers.