New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1899-12-31

worn away or as he is inclined to think. sunk
to their very edges in what was a food of in
vading material perhaps lava The break in
Hppalus and the filling of its Enclosure to the
same level as the outside plain he attributes TO
the same agency. The inference is drawn from
these facts that the influx Of the material now
constituting the surface of the seas occurred
long after the formation Of the now almost
Obliterated craters
Messrs. Loewy and Puiseux have suggested
that the bed Of the Mare Humorum. in which
the terracelike ridges are found, once at a
higher level than now, and for some reason sub
sided. The subsistence was attended, in their
opinion. with two phenomena. First. cracks or
assures in the moons crust opened. The rs
are regarded as products of this class. Secondly.
from one or more Of these crevasses it IS pos
sible that molten or at least viscid, matter
oozed out and slowly flowed toward the centre
Of the subsiding sea" The terraces are pro-
nounced the CONCEALED waves Of fluid matter.
The relationship between the rills and ridges is
the more credible because they are approx
mately circular and concentrc. Mr.. Maund'r
accepts the reasoning Of The French astronomers.
lie says
II appears that the basin now constituting
the Marc Hum1:Um has taken its present form
by q series OF Substances. Each suh.i"-n't
was marked at It's circumference" iN a tifNa-S'.
or fault. roughly circular in shape. am lh'st
crevass,s which were formed earliest and near
est the centre and which surrounded the deep
est subsidences, gave egresS % the Hluii ''
viscI matter OF 'he interior which Welled up
through them. filling up the creNasSes ana
forming ridges over them. Thes" outupW@
would become less and less the further the
crevasse was from the centre Of the Slb,ldeh.,.
and the less the depth 10 which the sinking ar
the crcvasse had taken place, until az IehElh Il
distance is reached at which no filling up oi the
creVasse takes place
Mr. Maunder argues that the untitled crevasss7,
or visible '.rls." are more recent than the seas.
and the seas are more recent than some Of tha
craters which they have either demolished or
submerged. However, there are other largo
craters in the middle Of sea, with their bot
toms at a much lower level than the surround
ing region. These cratcrs are pronounced more
recent than the seas. Moreover there are craters
which have evidently arisen since the rills We're
formed. Careful scrutiny Of the original photo
graph shows-though it cannot be easily d.
tected in the reproductions-that the tiny uplift
at the centre of the picture the line Of the
rlll which is furthest to the left has come up
through and completely interrupts the r
Two sets Of craters can be observed in the
bed Of the Mare Nubium. one is almost ami
hilated. and doubtless antedates the forma-
ton Of the sea itself The other set. including
one Of immense size and three satellites. rises
up sharply and is clearly Of more recent birth
than the sea. Mr.. Maunder thinks that the
greater volcanic power required to produce this
last mentioned group indicates that they are
older than the tiny crater on the line Of one Of
the rills. This latter is really identified with
the geological history Of the other big sea here
shown. Mr. MaunIer is thus led to conclude
that the Mare Nubium is much Older than the
Mare Humorum. and that the small crater on
the rl is one Of the most modern features Of
lunar geography