New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1851-05-15
SCIENTIFIC CONVENTION
-Testing Of the Amerfcan Association for the
Advancement Of science.
IT cINciEFATI.


CINcINSATI. Wednesday, way 7 = m
Attic afternoon session, to-day, al hour was
devoted preli1ninsrily to the examination OF Geo
logical Specimens, brought By Pfos. fandelb
Richd o ven, Mr.. P. Clark, Prof br1insrd' Col
Whistlesey. and others. Alarge number otspecl'
mems Of Virginia Coal were presented By Hr.
Clarke on behalf Of the Cincinnati Coal Mining
COMPANY. They were from the GuyandoHe River
Coal Region, about thirty miles from the Onlo
River. Regarding the fossils exhibited, Prot.
Agassiz observed that he had never seen 90 % -uy
psleontoloeical novelties at one time as had been
brouebt together on this occas on. Prot Henry
Hal and AgsssiZ were appointed 10 rePors upon
the specimens severally, and et their request
another apartment was obtained for the purpose
Of minute examination.
At4 clock the Convention came 20 oroel' suu
the unfinished business Of the morning was TAKEN
o. baivg naner ona NeU Cure for RIlr0dd
Tyacks by Rev Thomas Hill Waithsm Mass
ox.ssn,sd thnough Prof Prce. IL was read oy
P,esident Bacbe. with blackboard illustrations
The paper recommends TO civil engineers Two
curves for UNEQUAL tangents, IN which the degree
or DETECTION increases by equalincrements which
ore inns readily laid down, as usual, With the
theodolite and chain. Without diagrams aud
formula however, the essay does not admit oil In
telIeibe illustration. 1t will be published.
The most important of the proceedings so TAR
was now in order-being the Report OF the Com
mittee upon Prof Mitchell system of A'tro-
nomicAl observations. 1t will be remembered,
bv those who keep the record OF scientific inves-
tieatiops that at the meeting OF the Association
in NeW.Hayen last Summer, Prof. Mitchell b'st
announced bis wonderful Improvements IN the
observation Of Destinations and Right Ascen-
sions, and that q spirited and almost angry dls-
cnssion was thereby occGaioned among the con-
sentative members OF the body who were then
present The distinguished Mathematical FRO
te.sor of Harvard Prof PIERCE, waE among the
foremostin denying the feasibility ofthe newO 2ers
tions, and became their strenuous opponent; not
however, with the inordinate zeal which charac,
terized the action OF others. At the request oil
Prof Mitchell himself Prof. Peirce was appointed
Chairman of the Special Committee of lnvestgs'
ton That gentleman, in company with his coad-
tutors has had an opportunity, during the present
sessiOn of the Association In this clSy TO lnvest
gate the workings OF Prof. Mtchels Invention az
the atory at Mount Adams aud hss this
afternoon made Report in part on behalf OF the
Committee, in which high and unqualified com.
mendation is bestowed Jpn the entire system OF
the Cincinnati Astronomer. The final Report OF
the Committee will be rendered at the next
meeting in Albany in August next.
The reading Of the Report was interrupted by
frequent outbursts Of applause. 1t is as follows
REPORT or THE COMMITTEE UPON PROF..
MITCHELs SYSTEM OF OBSERVING DECLl.
NATIONS AND RIdHf ASCENslONs.
The Committee appointed for the examination
Of Prof Mi.cbels method of observing Right As
tensions and Destinations by the aid OF Magnet
ism, respectfully report in part
They have made a preliminary examination OF
Prof Mitchels apparatus and of his books OF OBJ
servaton. Every thing has been freely opened TO
a rigid scrutiny, which has been sought, earnest
w. by the Astronomer himself; and they have felt
h thasr dutx 20 inv
and even every possible source of doubt and error
with patience and fidelity. They would have
preferred to postpone all expression Of opinion to
the next meeting If they had nOt garded 1t as
being OF the first importance TO relieve anxiety
upon this subject az soon as they had proceeded
sufficiently far in their inquiries 10 be quite sure
of the final result They are not however, pre-
pared 10 enter into minute detail at the present
meeting, but must con6ne themselves to general
forms Of expression. They intend also to avoid,
at the present time, the consideration OF the
fN T. rSoiessvF MIIcheus apparatus for observing
Right AsceDsions il thought by the Committee 70
sustain ali his claims in regard to its simplicity,
accuracy, facility and dispatch. 1t is line speci
men of Ingenious contrivance, and the best proof
OF it's superiority in this respect is the fact that,
notwithstanding the rOughness OF construction TO
which the inventor has been forced TO submit by
his limited resources it rivals in the accuracy Of
It's results the most finished specimens OF skilliul
workmanship. By the use OF two pens he has
avoided all possibility OF ths peculiar error which
must constantly arise whenever the same pen is
used for recording the observations and the clock
beats By recording upon disc with pencil
which makes slight dot at a single swift stroke
he has reduced TO a minute quantity the pertur
batoDs in th5 motion OF the dlsc, which arise
from the act OF recording. The methods for ad-
justiDg the disc and reading its record exclude all
danger of error from imperfect centeriag, while
the ingenious apparatus for reading admits OF
great nicely and rspdty in the execution of this
task. The attention which has been paid 20 the
determination and elimination OF minute sources
OF error such as armature time and the like, de-
serves high commeBdation.
2 In regard TO the apparatus for observing De-
clinations, the Committee report, in some re-
spects, with less confidence, because the series
OF observations, although quite various, is not yet
sufficiently extensive. They think, howeve., that
they msy venture to report upon the probable
capabilities Of the apparatus, and the limit OF &C
curscy which it may be expected to attain, and
which it may already have attained. The princ
piles OF its construction are regarded by the Com.
mittee as perfectly correct, and as exhibiting
happy combination OF ingenuity aud originality
They are surprised and delighted at the simplicity
with which all danger Of error from eccentricity
or hexure 10 avoided, as partial equivalent for
which 1t may be important not to overlook any
short lateral motion Of the pivot of the telescope
In its socket In it's present form, the apparatus
must be considered to be purely dltferential, aud
TO depend upon other fundamental observations
for the absolute determination of the length of
it's arc. With this condition, the measurement
of differences Of declinstion may extend 70 the
degrees, and perhaps much further, without any
loss OF accuracy. The principal feature. which
chsracterizet this apparatus, and distinguishes il
from all Others consists in its admitting of the
observation Of ten different horizontal wires dur.
ing a single transit; and these observations are
made with great facility without mental tension,
and 90 close TO the meridian a. TO involve no diff
hculty in their reduction TO the meridian.
By an additional piece of mechanism for some
bservations, these may be conducted with IN
surpassed rspidity, and sufficient exactness, with
out risk OF confusion or any perp!exty Of thought
on the part of Ihe observer.
Finally, the Commit are not aware that the
hilfnrN, Of Astronomical acinnrn