Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-08-20
MATHEMATICS AND ASTRONOMY.

aria iano reclaimed by irrigation. The tend
ency to small farms and security of crops and
its relation to irrigation was also presented.
MATHEMATICs AND ASTRONOMY.
A Number Of Papers Read which Excited
Great Interest.
Mathematics and astronomy are the subjects
assigned to section A, but today papers before
| 1t were almost entirely astronomical in their
character, save Prof. Christie's mathematical
paper.
LITERATURE OF THE MATHEMATICAL SCIENCES.
The first paper read was by Prot. Alexander
s. Christie OF this city and was "On Digest of
the Literature of the Mathematical Sciences"
The professor suggested and strongly advo-
Gated as n much needed work eminently
proper to On association for the ad-
vancemcnt OF science tho forma-
ton from the abundance of literature
pertaining to the mathematical sciences
hundred or SO volumes This mammoth work,
| according to his plan, should contain every
| thing OF value hitherto done in the mathemati-
| cal sciences, logically and perspicuously
arranged in a homogeneous rotation, each
| truth or method referred to its discoverer
| and the whole thoroughly indexed. Mathema-
| ticians, astronomers and physicists throughout
| the world. he said, should be invited to aid in
the preparation of this great digest.
The cooperation of the British Asso-
should be secured. If possible, and
the work done under tho joint aud coordinate
direction Of the two kindred associations, the
volumes to be prepared and published In the
English language. Other nations should. Of
course, be accorded the right to issue the work
In their own languages il they bore proper
share Of the expense.
After this the astronomical papers had full
| swing and engrossed the sections attention for
the remainder Of the day.
LATITUDE OF THE sAYRE OBSERVATORY.
Latitude Of the sayre Observatory was
the rather peculiar title Of Prot. c. L. Dooittle
Of Bethlehem, Pa One would naturally ex-
pect that, however much difficulty therc might
be in ascertaininS the latitude of q ship at
sea, the latitude Of a good, solid OBSERVE
tory, built on terra frna, would OF all
| things be susceptible Of easy and
accurate ascertainmcnt. But Prof. Doolittle's
paper dealt with the new problem that is occu
| the world, which nigh. be vulgarly expressed:
Does the earth wobbleT' Diyested of its
bristling technjcalities the professors
exhaustive and carefully prepared pa
per detailed the results Of between
| eleven and twelve thousand zenith telescope
| observations extending over the past fourteen
years ut the Sayre observatory. Naturally
| this great mass Of material is Of extreme
value In the consideration Of the prob
lens presented by the, varying. latitude
which has been so generally observed. Prof.
Doollttle's fourteen years figures leave no
doubt Of the existence Of these variations and
| will doubtless aid in the solution Of the problem
world.
VARIATION OF TERRESTRIAL LATITUDE.
The paper presented by Prof. George c. Com
stock, the director Of Washington observatory,
Madison, Wis.,, bore on the same subject dealt
with in Prof Doolittle's paper. Its title was
The Secular Variation of Terrestrial Lati-
tudes." The purpose of the paper was to
show from existing astronomical data that
the terrestrial pole is in motion and
motion admitted at least approximate de-
termination. The data on which he based his
conclusions were recorded annual variations of
| minus three one-thousandths Of a second Of
| sandths OF second at Pulkowa. plus forty
two one-thousandths at Washington and
plus forty-three one-thousahdths at Madison.
From these facts the professor argued that the
north pole IL moving along the meridian at the
| rate of four and fve-tenths seconds a century.
The paper went on to point out the great import
ance OF this variation In latitude and program
Tor the systematic and thorough observation
OF the phenomenon all over the world, with
view to the better determination Of the elements
VI siC P0AtA iuotiOu, was Ouuiucu
QUITE DISCUSSION.
The class room in which the section met was
| crowded with people who wanted to hear these
two papers and after they were both finished
there was quite an extended discussion OF what
they had oiucidated: Each Of the authors had
to answer questions for some time after they
had finished reading. The discussion simply
showed how deep is the interest felt in the
subject treated Of in the two papers, no new
facts Of consequence being ELECTED by it.
GROUPS OF STARS.
"Groups Of Stars, Binary and Multiple" was
the title Of Mr.. G. W. Holley's paper. Mr..
Holley is Cornell University astronomist who
has new theory Of star groups. After refer
ring to several of the famous groups of stars he
says that the members OF all these systems
are supposed to be moving onward
toward u common center. Ii this is true.
he says rs they approach that center they will
be constantly more attracted to each other till
two celestial planetary systems will finally come
matter and crash of worlds Ho pointed out,
however, that there may be mistakes about
these star groups.
As an illustration, he told how when one is
on one Of two railroad trains on adjacent paral-
lei tracks, both trains moving in the Same
direction, but at different velocities, the other
train appears to be moving in an opposite
direction.
similar illusion might, he said. explain the
apparent motions OF some star groups. His
conclusion was that I'VE may reasonably ex-
pect that as succeeding ages with more perfect
instruments make US better acquainted with
the motions OF the stars and the geography of
the heavens, the number Of double and null
tifle stars will be less and less, while stellar
| systems will be constantly increasing in num-
ber."
sPECrROscoPE AND sPEcTRoGRAPH.
The next two papers were principally de-
scriptive in their character. Description Of
the Great Spectroscope and Spectrograph
Constructed for Halstead Observatory was
the title Of the next paper, which was pre-
sented by Mr.. J. A. brashear Of Ale
gheny. Pa. Az IL indicated by its title.
the paper was simply technical and
minute description Of the grand new
astronomical instrument built for the Halstead
observatory at Princeton, of which Prof G. A.
Young is the director. Great things in the way
Of finding out secrets Of the heavens are ex-
pected Of this new and powerful sky searcher.
The paper was illustrated with numerous draw
ings and photographs.
Mr.. Brashear also presented another brief
and technical paper, the second one being q
Mote on Some Recent Photographs of the Re
versal Of the Hydrogen Lines Of solar Promi-
nenceA" The photographs referred to were
taken at Kenwood observatory and were mainly
interesting - showing the reversal of the hy-
drogen lines displayed in the solar spectrum
NJ ~ =: A. q -