Helena weekly herald., 1888-09-20

The continents are white, the bodies Of
water black. The continents are here
represented by numbers as follows: l.,
Amazonis; 2, Memnonia; 3, Phlegra; 4,
Zephyria; 5, Acolis; 6, Elysium; Z, Hes
peria; 8, Aetheria; 9, Libya; 10, Aeria;
II. Arabia 12, Eden; 13, Edom; IA, Chry-
sia; 10, Tempe; 16, Thossis; II, Arcadia.
The three islands are as follows, in the
order of their size: Thryle l, Thryle II,
Argyle H.
| 1t should be explained that this map is
drawn on what is known as Mercator's
projection. That is, as if the planet were
| cylindrical in form, and its surface had
been peeled off and rolled out fat like SO
much paper. The map should be viewed
| with the paper held sidewise, with the
| South pole surrounded by the Australian
sea) at the top. This reversal of the poles
| is common to all astronomical maps, and
is the result of the reversing powers of
all astronomical telescopes.
81
Nebula are perhaps the best objects on
which to test new glasses; at least they
are the most delicate. As each new glass
is put on certain nebule parts that have
appeared filmy through other telescopes
are resolved into stars. But the favorite
object for astronomers in the planetary
system on which to bring new glasses to
bear is the planet Mars, especially when
Mars is in what is called opposition-that
is, when the planet, which revolves in an
orbit next exterior to that of the earth, is
on the same side of the sun with the
earth, and is 145. .000, 900 miles nearer us
than when it is on the opposite side of
the earth from the sun. In 1S45, when
%la % ha low Gin rr1a fr,
America, Mars and the earth were as close
val of about SO ,0O0, 900 miles, and the glass
was tested upon the planet and some new
points noted The Lick observatory was
not ready for observations till the middle
of July last. An opposition of Mars took
place during March, April and May; but
notwithstanding that they were rather
late for favorable observations, the astron-
omers of the Lick observatory made a
number of careful drawings of the planets
disc as seen through the instrument.
M. Schiaparelli, Of the observatory at
Milan, Italy, has devoted himself to the
study of Mars, and has made a map of its
surface, which is here given. The por-
tions which are given in black in the map
are supposed to represent water, the
white land. On the planet these differ
ences are, of course, very much slighter
in degree, and are differences in color. 1t
will be seen that the map divides the sur
face into the land and the seas, and the
lines which cross i'll every direction are
called canals, though this is q misnomer,
for some of them are 1000 miles long and
so miles wide. They are supposed to be
the same substance as what are called
Martian seas, because they are Of the
same color.
The transitions, however, on the plan
cts surface are so sudden as to seriously
interfere with the land and water theory.
M. Perrotin, director of the observatory
at Nice. declares that the continent
marked Ebya on the map, about equal to
France in area, entirely disappeared be-
tween two observations, the latter made
in April last. The truth is that the sun
and all the great planets which we can
see under favorable circumstances under
90 apparent rapid surface changes Inc
Variations on the disc of Saturn and the
sclouds" of Jupiter have long puzzled as,
tronomers. A few years ago great req
snot, anneared on the surface OF the latter