New-York tribune., 1878-11-08
THE PROCEEDINGS.

THE PROCEEDINGS.
The Academy met at 11:30 a. m. with 1ar
attendance, VicePresdent Marsh IN tue chair lhe
first paper OF the day was biographical memoir OF ITO
fessor Mahap by General H. S. Abbott. lie traced Tue
Iae nroessors career briefly through a brilliant course
"a cadet and then an instructor at West P0lhI io
lowed by q period Of study OF eDeneerlnS n iu,OI
He returned in $780, and two years later was appoVO
20 the Professionally of Civil and Military Engioeeis
Tho dntes of this position he discharged until MS ue"'h
sentember 1G 1871. To the development 0f military
science Professor Mahan gave the best years OF BIS me-
His teachings fruit in the service OF his pups On
the fields Nj XcO and tue war OF the feDehOh lhoush
Classroom he found leisure TO wrlte
many textbooks which well known by many persons
who never saw author Among these the best known
s bis Course Of Civil Engineering first published IN
1897 OF which frequent editions appeared until 1868
The last years OF his life couded with fears that
his age would lead TO his retirement from duty' Ihese
were realized In 1871 aud the effect OF this blow was the
unsetiDg Of his mind which led TO his SUICIDE III tne
fal OF that year.
A STRICTLY MATHEMATICAL PAPER
Tho next paper was by Benismln Alvord' Paymaster-
General OF the United States Army The paper was
continuation of presented at the Apfl meetng' on
"Tne Intersection Of Circles and the luteraecton OF
spberes." 1t was deemed remarkable as demonstrating
is propostous by pure geometry, when in these days II
is tie fashion TO employ algebraio solutions With com
peated diagrams he made several dem0nstratl0ns re-
arEiug with dry that he had secured $40 sou-
ijons 10 one figure on the board but he would
tent himself With giving the Academy one Tie mem.
relief.
INSTRUMENTS OF PRECISION AT THE PARIS EXPOSE
TON.
George Davidson astronomer in charge OF the United
staes survey OF the Pacific coast then gave some ooser
yaons on instruments Of Precision at the Paris Tx
posouS He aaid thOt he went abroad at the request
Of the the Coast Survey 10 ascertain
whether In Europe better instruments were made than
here In his previous experience nc had fOuhd rev I'D.
In
theOdOlites 10 detect errors In some mere mere
were eIIoIs W VI , ben n - stated Ib9t sec
ond at distance of 16O miles means Iour lte very lew
new designs or arrangements found ID instruments
of urrcsOn at the Paris Exposition. One notable eX
eeption In effort toward simplicity IN structure
pou,s In EurUps said NJ. Davidson "Iound it mpossi
bic TO observe inc system OF graduating machines. All
amiUalon OF their work. As result OF thus in ali in
struments precision OF the Exposition, am positive
ana one of the urymen conf III, my OpinOl-that the
juries awarded their veTdcts on the app cut goOd con
makers shOdd have preferred 20 see them tested Tor
practical efficiency. To give an instance; On VerueT
Scale mdera lDagDfying glass, the figures were found
TO have been punched III, mus destroying he RWHut
tiou. Another exhibition OF careless wOlk was this
ing drawing, eoubted uinety-three screw beads. The
number OF pieces Of which tins Was composed may be
drawing instrument tapped on the shoulder
and informed that oe exhibitors refused TO ALLOW draw
exhibited but it had no authority.
To sun up my conclusions, may say that while saw
much ldeep interest at the Exposition there war 10
single InstrlimenI thai would recommend for imIu-
lion What principally learned was what not to copy,
and convinced that do NOT need to 60 10 Europe
FOR Instruments Our OWL observers ana mechdn-
lead in tue scientific race both appreciate the fun
damenta IDEAS OF simplicity fewness of parts, harmony
Of proportion in the accuracy OF division anu leyel,
adtguaey Of optical power 9nd mfthematcai precision
The paper discussed by Professors j. H. c. Coffin
and Charles :. PclrCs.
aud New E-laUns 10 LIyiHg Forms" was then read by
Professor j. s. NewberTy, geOIOg1st of Columbia College
He illustrated ms remarks Dy plaster cass ol many
fossil forms.
ouAYTrrATIvE ANALYSIS OF WHITE LIGHT.
At the afternoon session Professor o. y. Rood, Of
Columbia College, spoke on "a Quanutauye Analysis Of
White Light" He said that he mad been trying 10 obtain
qualitative analysis Of white hght-hOw much light
there was ia yellow light; how much in red, etc. 1t
was that there was no definite standard Of
Those who have cultivated the sense Of color can
easily distinguish dehcate nts, and artists are able 10
detect the pigments that have entered INTO the cOors
used person with cultivated sense OF color can te al
English vermllion. Tine standard OF color among
PgISSV PPtSSey do not dispute about shades Of color.
ghe speaker determined the color OF various colored
disks by placing them on spectrum tor comparison
aud they fell in the exact spaces where they belonged
From bis experiments he found the quantity Of the yar
colOrs beam of white light, and learned that the
warm cOlors greatly teded the cold colo5s .,,
Alexander Professor Perce said that tn observations
OF Professor RoUd opened up new branch OF physics
science dealt only with rude methods Of COmparison In
this branch there departure 10 new aud delicate
known 10 physical science.
OTHER PAPEKs AND ADDRESSES.
Then followed an address by Professor stephen Alex
snder Of Princeton n. j. "RccapitulatiOn OF
Of the authors views the origin of the forms and pres
nt state Of many the clusters of stars ana several Of
tne nebul source Of solar heat and drift of the stars"
The professor OF the peculiar speakers OF the
Academy. He fond Of interardiDg profound discus
sons with qups and Of apt quotation and bts
OF humor dry enough TO agree admirably with the
tIre of his subjects His funny points are made more
lddcrOus by m manner which is the very essence OF inc
solemn and venerable
Professor NewDerry, OF Columbia, next spoke On
Some MOOted Points III Geology" He dwelt on the dll-
ference classification of several groups OF rocks In
thIs State and Ohio. He argued that the Cincinnati
OF Ohio to be regarded equivalent TO inc
whole series OF lower siluran lmeStOne IN Newly York.
was not TO be held minor division OF the lower
biuran He also gave many other instances OF these
differences OF opinion, which the acrimonious
dispute ever ligfe beds OF Colorado which
pretty quarrel tnat 1t seemed pity TO settle IT, as II
OCCUPATION 10 nunuer OF geoiOglsts. From his
observations and those of Professor KING and Others
he had come TO tie conclusion that these Oeds were
,ereaeeOus and tertiary. Another mOoted point was
whether had been two lee periods or one The eN
deuee gathered far he thought showed that there
being due 10 and advance Of the same glaciers
IN the same period The address was discussed BY Pro-
fessOr Cope, Of Philadelphia.
few notes on Herrings theory OF cOlors were then
given by Professor o. ~ Rood, OF COlumbla ana Pro-
lessor f. D. Cope OF Philadelphia, read paper Tine
Character Of the fberamOrphOus Reptiles"
The Acsdt my then adjourned, 10 meet TINS morning,
when papers will be read b. Professors T. ID. Cope,
Alexander and Guyo This session will close The
present meeting OF the Academy.