The Portland daily press., 1892-07-29


complete proof by erecting structure
corresponding in form to the demon
,stration in Euclid that the square OF
the hypothenuse is equal to the Sums of
the squares of the sides OF right-an-
igled triangle, which would prove their
acquaintance with geometry. But why
should they do this, when it would be SO
difficult for us to reply?
At the very time they are the most
easily seen by us we are so nearly be-
tween them and the sun as to be almost
if not quite invisible to them. If we
knew that they possessed a telescope as
large as that at Mt. Hamilton it would
be exceedingly difficult for us to con-
struct geometric diagram which they
could see at the distance the earth
would be when it had escaped the SUMS
rays They might well forego the at
tempt to communicate with us, know
ing that added to the uncertainty of our.
ever perceiving it is the almost positive
certainty of our being unable to reply
ito it.
The two extremely minute moons of
Mars were discovered by Prof. Hall
lat the National observatory in August,
1S77. Since that time there has been no
discovery of third moon. The ques-
tion then arises whether the discovery
of one or more additional satellites may
mot be among the results of the observa-
ltions of the present year.
The first observations of Schiapareli,
(which have attracted SO much atten-
ton, were made ten years ago with a
telescope of only eight inches aperture,
land have been partially confirmed by
other observers during subsequent OPP
positions and with much larger aper-
lures. The so-called canals" had long
been known to exist, although the term
has been only used for convenience,
Since we have no means of knowing
that they contain water. The pecul-
'iarity noticed by Schiaparelli, Perrotin
and other observers Is that lines par
Iallel to the canals are seen in many
ceases, forming what is called the duph-
cation of the canals. The Importance of
this discovery consists in the fact that
these duplicating lines are not perna-
.nent, but are subject to changes APP
parently corresponding to the sea-
son Of the year in Mars, the lines
making their appearance soon after the
spring opens, lasting during the summer
and disappearing upon the approach of
winter. Observations Of our own moon
show great changes at different times,
owing to the angle with which the suns
rays strike the mountains and valleys;
and it is not impossible that the OBJ
m,
similar cause. The presumptions, how
ever, are in favor of the theory that it
is the growth of vegetation that causes
the lines to appear, and the falling of
the leaves which causes them to appear.
It is In order to determine by an accu-
mutation of facts whether this is the
true theory, and whether we have this
visible evidence of the existence of veg
etable life upon our neighboring
planet, that every large telescope all
over the world will probably be direct
ed to the planet Mars during the COM
ing week, to confirm and add to the rev.
Citations already made.
: Small telescopes will show the oceans
and the continents of Mars much better
than at ordinary times; but any tele-
scope, in favorable location, with an
aperture of eight inches or more, may
aid in giving us testimony upon this
point of vital interest. While much de-
ponds upon the telescope, much also de-
ponds upon the observer, and upon the
attention of the observer being directed
TO the point to be examined. It usual
" requires a very much smaller aper-
ture to see an object once discovered
than was required to make the original
discovery. And still more depends on
the nearness of the planet If the adj
vantage of telescope were in proper
ton to it's aperture, twenty-eight inches
aperture now would be equivalent to
thirty-six inches aperture two years ago
But owing to the increased thickness OF
glass to be traversed and other causes,
still smaller apertures, such as that at
Washington or at Princeton, can now
show more than could be seen in the
Lick telescope when Prof. Holden de-
| clared that he had had such views OF
Mars s'as no other astronomer ever be-
fore had" And yet the Lick observers
will retain their prominence. While
from others we may expect many addi-
tional facts, it is still to the Lick OBJ
servatory that we must look for the
best evidence of the condition of our
sister planets.
| !, 1t was not until three months after
Mars was nearest to us in 1883 that it
was possible to make regular observa-
tions at Lick observatory. Atthat time
the earth had passed SO far away from
the planet that the advantage of that
immense telescope could not be utilized.
1T was two years before the earth
again overlook Mars in its passage
| around the sun, and at that time
its distance from the earth was
so great that it was necessary to
wait two years more for the opposition
of 1892. at which time the circumstances
will be more favorable than for many
years to come On June 26 we had
already approached as near to Mars as
when nearest in 1890, and ever since
that date the observers at Lick observ-
atory have had a better opportunity
to scrutinize the appearance Of the