New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1898-05-08
THOSE ODD CANALS OF MARS.
ARE THEY EVER REALLY DOUBLED. AS
SCHIAPARELLI SUPPOSES?

RECENT EXPERIMENTS py \ FRENCH AsTRoNo-
MER. ANroNIADI. SUGGEST THAT THE PIE
NoMrxo~ is AN OPTICAL ILLUSION
No mystery, perhaps has puzzled the astr"n"-
mers more during the last twenty year" IMAM
the nature If the canals Of Mars. The most III
3xplicabic feature If thes" singular planetary
markings. without doubt. is the reported uou-
ling Of ;hc lines at certain times S'hiaparei''
who was the first TO mcntior this str'nge ph'-
ronenor. declared that he saw no less IMAM
twenty canals doubled during the earlv part VI
the year lSS, when Mars was uncommonly
fayorably s;uated for observations
For several years this assertion was WITHOUT
c,rrororation. Compositions Of the planet al
ford the only chance to examine Vt advah-
tagcously and these occur a intervals 81 more
than two years Moreover the planet Is turther
away from the earth at one opposition IMAM al
another AMI is higher up above IN" s"u'her"
horizon At on Of these times 'han ~ announcer
SIN another embarrassment to observation. ac-
cordng 10 Sc'iaparclli. is the fact that the al.
legged duplication of the canals is seasonal
,vcnt en- Mars. and the proper s.rson ."r IL does
not always come at the sam" Time Il" i" 'pp'
silion However, on two or thre" occasions
within the last sixteen years. il has been re-
ported that other astronomers have seen one 'f
more Of the NlrtiaH canals double something
like corr lbcrlt.on has been given to N original
story by Per.otin Of Nice. Holden Of the Lick
Chscrvat ry STANLEY Williams can Eng,ishman),
and others. Nevertheless. this has not entirety
satisfied certain sccptcs and the iinp"SSihly
Of furnishing thoroughly satisfactory theory
TO account fpr Tho phenomenon Of termination"
has mad tn stories in regard 20 il seem moro
Incredible
MIN Nl,sr q
omers that This curious development Is merely
AN opti.al Illusion e som, sort several cX-
,larati.ns IF this KIND have been offered. one
which can hardly fail To- attract muc'i attention
has been advanced within The last few weeks by
f. NJ Ant n'adi. an assistant IF Camille Flan-
marion at The Juvisy observatory IL france
This theory. while put forW ard in only pro-
visIonaI way. ras at Last tn" merit of being
backed UP 10y experimental evidence ii. An
,ori,,li found the key 10 his explanation III a
remark Of DE Zoe. quoted by Flammarion III
the iatteI's La Plant,c Mars" DE Doe at
tributcd .he ,,oub.ings 20 secondary Images Tx
those which CORN IN an observers ey" when rH-
arnining a straight line. drawn Win INK On
whre cardboard. placed nearer or further from
the eve than is necessary To sccu-c distinct
vision In oth.r words. the duplication Nigh:
be the res,l, If imperfect Focusing If the telc-
scope
Acting on this hint NJ. AntOn!adI made draw
inrs Of sngl, canals. with dots at IN" inters'c-
ii ms. placed lis sketches at 4 distaLce Of ~
feet FRI IN his Telescope. and then examined them
He discovered that by varying the position o.
his ,yepiecc only one-hundredtn Of an inch ne
could change the image presented to his eye
from a single 10 a double one. The dots.
which correspond to what have been called both
"lakes' and ''oises" were duplicated as well as
the canals He says:
The phenomena Of termination Of the lakes
and canals Of Mars being pr"ducibic on paper
By very slight focal errors. We should examine