The times. [volume] (Richmond, Va.) 1890-1903, 1890-11-06
OUR KNOWLEDGE OF MARS.
Precisely What Can safely Be said About
Our Neghbor Planet.

The planet Mars, says John L. Richie
.Jr., in the Boston Commonwealth, during
the iew years past, has received consider
able attention from journalists aud writers
who have discussed ii with that tendency
toward the sensational which is so char
acteristic in these days. A plain state
ment, therefore, OF our present knowledge
drawn, AZ may be. from the writings Of the
observers themselves, will not be out VI
place. While II Is 10 be regretted that absD-
lute conclusions cannot be deduced from
our known facts, this failure Is OF no great
moment, for it is better 10 know little aud
know it WELL than 10 know great deal
and have il not true.
The planet Mars Is our neighbOr In space,
and presents such anal0gies t0 our own con-
ditions as 10 be Of great interest 10 US. In
size il Is inferior to the earth; in climate
not widely different; and IL is by no means
impossible that life on Mars may have
reached the perfection which IL enjoys here.
Its time of revolution abyut the sun Is two
years and its distance as compared with
that Of the earth about as three 10 two. Al
conjunction its disc measures about four
seconds of arc, while AT opposition IL u
sometimes as large az thirty seconds, hence
il is more easily observed at these times.
White spots were possibly indicated on
drawings Of Mars made in the seventeenth
century, and early In the eighteenth they
were positively shown. Two Ot these
spots have remained with constancy. and
have been termed the snowy poles, which
are generally considered as analogous 10
our own poles. Since the map of Nader
In 1880, drawings OF Mars have been made,
until many hundreds are in existence, AMI
If due dependence could be placed In tho
accuracy Of the representations much in
formation might be deduced.
Observers have noted changes In tho
physical aspect OF the planet. Some OF these
1.-THE slow variation Of the polar caps, for
Instance) are relatively easy 10 follow.
Others are more rapid, being accomplished
in few days, while other effects are differ
ent from one day % another. Among tho
last class is the so-called doubling OF tho
canals. Finally, other changes are found
10 coincide in time with the period OF rev, :
luton. Many difficulties lie in the way OF
an accurate and complete study OF these
| changes. Observations are limited 20 cer-
tain hours OF the day, and also 10 hat period
OF four months when Mars Is near opposi-
ton. The oppositions occur In different
parts OF its orbit and under varying inclina-
tions OF its axis, so that at least sixteen
years Is necessary for the complete inspec-
| ton OF the planet. In addition, there ara
our conditions OF atmosphere, and finally
| the difficulty in comparing the observations
made by different men with different teles-
copes on account Of instrumental and per-
sonal peculiarities.
Upon certain differences In color rests the
notation continent" sea- ''canal,' -
''island,v etc. This notation must be re-
garded only as matter OF convenience, and
positively does not imply anything with
reference TO the physical condition OF the
| surface Some regions usually of small
area, are sometimes seas, sometimes con-
tinents. In the light Of this statement II ID
interesting to note NJ. Flammarion's posi-
tion In paper in the Complies Rendus In
1878. This summed up the known facts .,
| that date.