Evening star. [volume] (Washington, D.C.) 1854-1972, 1878-04-18
The National Academy Of Sciences.

of the National Academy of Sciences yester-
day was by Prof. Alex. Agassiz, entitled a
Preparatory Report in the Deep Sea Dredg-
steamer Blake, during the past winter, in the
Gulf of Mexico and the Gulf Stream An
interesting account of the methods employed
given, and the scientific results of the expedi-
tiOn were slightly touched upon. To increase
tpe rapidly and certainty with which sound
ingS were made. and also as an improvement
In the dredging work, wire was substituted for
rope. Specimens of dredgeS were exhibited
ny PE9l: @ @AMgasslz; aga who, by this means, and bv
be highly appreciated by all of the audience
"Abrasions on the coast of North America"
was discussed by Professor George David
SSn wao ndSf dsserbed the elevated terraces
North America, and ascribed them to the ac-
ton OF ice in the glacial period: A paper on
woeots a GbSs sSd ana on The Pg
section of Circles and the Intersection of
Spheres" by Gen. Benjamin AlvOrd, brought
the scientific season to close. The last pa
DE- Hllgard. The results were reached by old
style geometry and not by the analytical
At half-past four o'clock the scientific ses
sion was adjourned, and the Academy resumed
its business session.
THE FOLLOWING NEW MEMBERS
We're elected: Gen. Francis A. Walker, of
Yale College, New Haven, Conn. Prof. John
Trowbridge, of Harvard College, Cambridge :
Mass; Prof. John LIE COnte, president OF the
University of California, Oakland, Cal.
AT THE MEMORIAL MEETING,
m, IN All Souls church last night, interesting
tributes to the memories of deceased members
were read, as follows: Biographical Memoir
or Louis Agassiz; second part, relating to his
life and work in America" by Arnold GuyOt !:
Memoir OF Jeffries Wyman," by Asa Pack
ard, jr. In Prof. Packard's absence, this me-
mOir was read bv DR.. Elliott COues.
TO-DAYs PROCEEDINGS.
Inc Academy OF Sciences met at quarter of
T1nr nIrl,r DunF
cambridge, Mass: Prof. Arnold GuyOt of
Princeton, \: j.; Prof Stephen Alexander, of
PrlGnceton, \, j., and Mr.; Charles E. Peirce,
have been added to the roll in addition to
those previously published in the STAR Elec-
tlons, to MI the tWooflces vacated by the ex-
blfatlon OF the terms OF the incumbents at
DR.. Gibbs and Prof. Hilgard having positive
ly declined reelection to the offices of vice
iha homs Hf Tse osgs
ven, Conn, was elected vice president, and
Prof: j. H. C. Coffin, L. S. n, (retired,) of
Washington, was elected home secretary for
the ensuing six years.
resolution of thanks to the retiring Off
GERS, for the zeal and ability with which they
had discharged their duties for the past six
years, was unanimously passed.
Members of the Council for 1889 were then
elected as as follows: Prof. s; F. Baird Dr.: Wal
e9tt Gibbs, lrof 4 AsaPh Hall Prof J. Hill
comb. The officers of the Academy are now:
Joseph Henry, president; o. c. Marsh, vice
president r. A; /. Barnard, foreign secre-
tary j. IL. Z. Coffin, home secretary: Rogers
Falrman, treasurer. and the council as above
AT THE SCIENTIFIC SESSION.
.,pJln ra01' 81 NGMcom9 N1o deilvered lecture on a
He Illustrated his remarks by diagrams on the
black board. and was listened to with great
attention He made many valuable suggcs-
tl0nS IN respect to the best method of deteTnl-
ming this important constant in physics and
astronomy,
After Prof. NewcOmb had finished his lee
ture an interesting discussion on the subject
by other members of the academy followed.
E. c. Pickering, Boston, Mass. Prof c. II. F.
Peters, Clinton, n. Y; and Mr.. s. z. Langley,
OF AHeghany Observatory, participated. Sew
MeWcOmb were made and suggestions offered.
!he Professor was heard in reply to the OBJ
Jections. and the debate was quite animated
MARS AND ITS SATELLITES-INTERESTIN PAR
TICULARs AsCERTAINED BY PROF. HALL
:, Since his discovery OF the satellites of Mars.
Prof: Asaph Hall has been engaged at every
to determine their orbits, distances aid peri
Odic times. Though his labors are not vet
completed, enough has been done to indicate
that these newcomers Will enter, with all their
characteristics properly described, into the
pages OF the next text book on astronomy In
his recent address before the Academy of
Sciences, Prof. Hall gave, an interesting de.
ScflptlOn OF the methods OF computation which
he employed and the results obtained. The
elements of the orbits of the satellites were
III hrst aSceIlalned with considerable accuracy
OF DeimOS, the time of revolution around the
planet was thus found to be 80 hours IS min
@tes sais Tor fhob3s the inner satellite, hours
mentS We're determined the method followed
was to use first, only the observations taken at
washington, because this series was by far
made. Moreover it would have been cen yerv yerV
difficult to unite the observations made at
dI1erent points into one group. Those at
WI. Wa.shhlngton, hag, @ were taken between August 1lth
and october 3lst. There were so observations
OF Demos, and 80 of Phobos The results of
these labors were then compared with the
approximate elements What are called equa-
were computed between these residuals and
the elements. There were 9S equations for
Defines and e for Phobos the eq quations con:
equations was solved by what is called the
method of least squares, in order to get the
most probable corrections of the assumed
were involved Years Of watching f''iui and
months of complicated computation, are
ffeqHbbedh bch 70 20 ascertain aa astronomical facts
h0ufS study. The corrections were then ap-
plled to the assumed elements and gave the
hnal elements which cOrresponded very well
tnns Wltn the results OF the Washington observa-
be, Tor DeimOs 30 hours II minutes 1886 sec
9nds, ds and and for Phobos hours SO minutes and
ac'oi SCSOuuos lie INSTANCES OF the Satellites
from the center of Mars when that planet is at
distance OF unity from the earth were found
70 pc, Tor DelmOS, 32354 seconds, and for
Ph0bos. l2.953l seconds. By means of these
periodic times and distances in yery few
minutes the mass of Mars can be computed,
Using Demos in our calculation the value of
mars is found to be One-3095313th from Pho
DOS lt is ascertained to be one-3O7S455Ih:
the mass of the Sun in both cases being
!aKen Tor unity as is the custom in as,
trOnOmy. These values of the mass of
Mars Mars are probably much more accurate
than any that have ever before been
computed. They show that the mass OF
THE PLANET Is SMALLER
1han has heretofore been assumed. The
former values were found by the perturbations
when Mars exerted on other planets. About
the beginning OF this century Burchardt gave
Its value, obtained in this way, as One-26SO00Oth
and some years ago Leverrier, the French
astronomer, after laborious calculation
found its mass tObe One-29S0000th, value only
little larger than that given by the motion OF
the satellites. ..~
CURIOUS FEATURES OF THE SATELLITES.
Another curious feature is that the orbit of
the outer satellite is very nearly circle,
Whie that OF the inner one seems to be deci-
aedly eccentric, or to be an ellipse. Attention
Is Gaiied TO TINS point because such discovery
IS hafdiy what would be expected. The at.
tempt to explain the rapid motion of the inner
satellite by assuming the existence of a resist
Ing medium around Mars would here be met
by this objection, that although a resisting
medium would indeed shorten the time
OF revolution it would also diminish the eccen
tIlclty OF the orbit that WI p,i0bf o,nno,a