The Portland daily press., 1896-07-11

| mers at the Lick Observatory, on the
top Of Mount Hamilton, in California.
They have applied their resources to the
photography of the moon with roDnarka-
Bile success. and some Of their pictures of
our satellite have formed the basis upon
which DIR. Weinek has produced ex-
! quisite drawings of the lunar features.
| AS, perhaps, the latest book on the to-
biography of the moon, may mention
the elaborate work by Thomas Gwyn
Elger, who is himself one OF the most as
| siduous of lunar observers He has col
leoted together the most interesting facts
relative to the topography of our satellite.
am much indebted to the various au-
thorities l have named for information
which I am utilizing in the present
paper.
When we look up at the full moon,
even without calling the telescope to
our aid. we at once notice the presence Of
a number of large dark patches. 1t is
certainly true that there are no sheets of
water nor anything like water at present
visible on the moon, even with the high
est power Of our telescope. In fact. there
are sound physical reasons why 1t does
not seem the least likely that there could
be any water in the fluid form present
in our satellite. At the Same time the
appearance Of these dark spots, in days
before telescopes were employed, suggest
ed that those objects were basins of
water, and accordingly they were an
GENTLY called ''aess." In modern days,
| hou
retained this name, or it's Latin equiva-
lent, to designate these peculiar dark
| tracts, notwithstanding the absence of
water Many of these are CT enorm Gus
extent, so-called seas, to be reokoned in
thousands of square miles. In fact near
| ly half the visible surface of the moon is
30 occupied.
| 1t is still an open question as to wheth-
er these reg ions have ever been covered
with water. No doubt it seems the
simplest superstition, SO far as certain
phenomena are concerned, to believe that
they are the basins in which great seas
did once roll, but that as the moon has
gradually cooled down from a primeval
state in which it was largely composed
seas penetrated into the interior, and
there entered into chemical union with
the materials which were crystallizing.
Tt certainly does seem that whole oceans
full of water could have been thus dis
posed OF. There are, however, many who
believe that these dark regions are due to
| the pouring forth from the interior of
vast volumes OF molten lava whion
spread over deep hollows, burying more
or less completely the objects which had
previously occupied them. In some
places Indications are found that these
regions were once occupied by other
structures Of which only vestiges are any
longer to be disoerned.
There can be no doubt that these So
called seas lie lower than the general
surface of the N Don. If water was to pc
poural on our satellite. 1t would certainly
tend to fill the basins once again. Close
examination of these remarkable tracts
show that the grayish, slaty tint that
they usually present is by no means uni
form. AS Mr.. Elger remarks: II have
| frequently seen the surface in many
places covered with minute glittering
points of light shining with silyery
lustrs, intermingled with darker spots
and network of streaks, far too delicate
and ethereal to represent in drawing"
In certain places in she lunar s'seas'
regions of yellowish or gre enish tint
have been occasionally noticed when the
| illumination was under suitable condi-
tions. Such tints have sometimes been
attributed to the possible presence Of
some form of vegetation, though this
would hardly DO compatible with the
absence of a lunar atmosphere. ny
The grandest illustration of this class
of objects is the great Oceanus ProeeIla-
rum, which covers an area not very
different from that occupied by European
| Russia. If. however we desire to look
at one of the objects of this class which
seems most alphabetically to suggest its
origin to have been an ancient sea basin,
I would specially call attention to the
| Mare Crisium. 1t needs but little @ fort
of the Imagination to fill this remarkable
| gulf with water, and then to see how
it's margin forms the cliffs against which
! the waves have hurled themselves for GEN.
turies. Close examination reveals that
the floors of these 'ssas'' are marked
over with various Irregularities, SO that
when such features are spoken of aa
smooth, it must be understood that this
is merely by way of contrast to the ex-
treme ruggedness which prevails oven
the greater part of the lunar surface.
The most characteristic features of the
scenery of our satellite are, however. the
remarkable objects which are the results
of volcanic phenomena. There are
many classes into which these objects car
be divided, but Tor our present purpose il
WILL perhaps, be sufficient if we at
tempt to give some brief account of what
may be called the walled plains, and OF
the volcanic o1aters properly SO termed.
According to NJ. Elger, the most perfect
example of a walled plain on tbs moon
is the great object known as PtoleYnaeus.
| uly