New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1851-05-15

Ah-
Ths cnrvss for Toronto and Philadelphia present
q remarkable acc. rdance in tbe times OF maxi
mum and minimum. and in the motion Of the
needle between these times-the slight d,ues,
ences being in fact apparent only. and resulting
f-or, the fact that the observations at TorontO
were made hourly and those at PnlisdelPhla 81
honylv All the conclusions in regard % the e.
fact ~ ,essops and the like, which have been
5,sxn nv Col Sabine from the Toronto observe
,iop1 are deducib.e from those az Philadel phls.
The relation Of the motions OF the needle -
Hobart Town. in so1sh lat's1de, nearly the sauS
as the north latitude OF Philadelphia, Vas pointed
out ,
From the publication Of the very extensive and
valuable series Of combined observations which
ave no in part il the hands Of scientii' men Tor
discussion and mparison, the most important
results may be anticipated. A. NJ
CIScIsSATI. Thursday, Msys.
In closing yesterday for the last Mail, want Of
time compelled an omission Of the interesting re-
marks which folio wed the reading Of Prot
PEIRcE's Report on Prof Mischels Systems OF
Observation. The annexed running sketch con-
veys an idea of the impression made By thai Re
port. It will be noticed that Prot. Mitchell bore
bis blushing donors with marvellous simplicity
and humility.
Prof BAcHE remarked that the value of this
decided and perspicuouS report was enhanced oy
the cool, investig eating character o. the members
OF the Committee, and the practical and theoreti-
cal knowledge which they had brought TO their
task The circumstances attending the reception
of the description Of Prof MitchelE invention az
the New Haven meeting further increased lts
value. 1t was not surprising that those versed
in the methods Of Astronomical O0serv alton IN es-
tabshed use should be ske ptical In regard 10 the
performance of an apparatus avowedly construct
ed with imperfect means, and startled when It's
results stated as vying with those OF perfect
Instruments imported or made at a great cost.
These opinions wereftreely expressed, aud no
considerations Of private friendship were allowed
10 interfere with q protest which seemed to many
members OF the Association 70 be necessary
against the pretensioDs thus set up. Professor
Mitchell did not doubt but with manly love OF
truth, cOurted examination and invited those who
objected 20 make the closest scrutiny OF his re-
suits. This has been done at the present meeting
The Committee has carefully and with great mi
nutepess investigated the whole apparatus, Its
action and its results; they have given cOnsid-
cradle portion Of their time to this investigation,
and now unanimously report that they are salts
fed that the claims set up TO this method az
marked improvement are real. 1t goes out then
with the stamp Of this Association; it has passed
q critical ordeal, and stands by its mt rts as one
OF the most remarkable steps ever made IN our
country in the progress of Astronomical observa-
ton.
Prof mitchell remarked that, on presenting
to the American Association an account Of the
new machinery for the registration OF Astronomi-
cal observations in Right Ascension and Oeclina'
ton, he was not at all surprised that the results
reached by such apparently inadequate means
should have produced a powerful revulsion and
. oks al hov ariaa rahallTnn
against these presentations, in the minds OF the
most iudcious and conservative members OF this
body. But he had nowhere else 20 60 but to the
American Association. The instruments were
complex in their character, difficult TO be under
Stood and requiring minute inspection and per.
sonsl examination for their fall comprehension.
And when doubts were expressed by high
authority, the only course was to challenge the
most rigid examination. The high standing OF
the Chairman Of the Committee to conduct this
examination, and his report has just been pre-
scented. Prof Mitchell would not attempt to ex-
press the qualification afforded by the confirms
tion OF bis own views OF these methods by the
opinions OF such gentlemen as those composing
this Committee. He could only say that how
ever severe the demands OF the Committee might
be on the performance of the machinery his own
demands would be infinitely more stern and IN
yielding in their character.
On motion Of Prof COAKLAY, it was resolved
10 OueT tue hcPOIb VI IIOi L lh1E " bHo phPcls
of this City for immediate publication.
A paper was also read at the afternoon session
on the Determination Of the Velocity Of Sound
1t WAS by Prof. BAcHE, and the following is an
abstract
DETERMINATION OF THE VELOCITY or SOUND
BY THE METHOD OF CONDOLENCES.
This method, said Prof Bsche, occurred to me
about the year 1882, when observing the march
- 49, e -. Ill., - W..
Point, to martial music and az quick step At
FIRST the LET'S foot brought to the ground in the
cAdences OF the music, and az the music and
marching body receded, the right foot appeared TO
strike the ground In the cadences. There was
succe ssion OF such alterations This suggested
the idea that by providing a regular series OF al
ternAtiDg motions, any remarkable phase OF which
was simultaneous with a sound, and observing at
suitable distance corresponding to the loudness
OF the sound and with proper appliances to assist
our sight, & very simple and exact mode Of do
terminiDg the velocity of sound would be had
Tn method is OF such easy application that il
might be used to investigate many points yet re
curing full experimental determination in regard
TO the effect Of temperature moisture, the force
and direction Of the wind, &c.
Prof COFFIN remarked that by connecting the
pendulum proposed to be used by Prof Bache
with gAlvanic circuit breaker, the signals could
be conveyed to any desired point and registered
there, TO which Prof Bache assented as an inter
esting development of bis proposition.
A paper on the Fossil Rain marks in the Red
Sandstone Rocks Of New Jersey and Connect.
cut was presented by WIN. c. REDFIELD.
Esq. OF New.York. Mr.. Redfeld referred to a
abort notice Of some newly discovered 6sh-bedI
and fossl iOotmRrk in the Red Sandstone At
PomPton, in New'Jersey published by him in the
44th volume of sillimAns Journal, First Series,
in which be had stated that while there was great
variety in these impressions of drops Of rain and
bail as regarded different slabs, some OF the spe
cimens were Of the most perfect character;
while In not few cases, the oblique form Of the
impressions served to show that the droos had
been driven by a stray wind. His frst obserya.
tons Of rain marks we're made in ls42, in company
- L.. Z IL.