New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1857-08-19
AFRICAN ASSOCIATION FOR THE AD-
VANCEMENT OF SCIENCE.
FOURTH DAY.

MONTREAL, Saturday, Aug. Is, 1857.
ID. HASI, yesterday afternoon, was allowed a few
Dnutss to give his views storms. He took the
hesY st O'Clock. Stated Mr. Red6elds theory in such
. wsy that Mr.. Redfeld could hardly have recognized
l. He said that he could not believe in the circular
Aeory Of travelling storms, thinking that they must
move not in circles but in eyclodal curves. He
kibited diagrams showing these curves. That the
violence was greatest in the center of the storm was
ven known, whereas on the cyclone theory il must be
greatest at edge. lDr Hares crava. became
bosed; President Caswel kindly drew his attention to
i, and he took it off and replaced it, wrong side up,
while spesking.] DIR. Hare, after demonstrating what
he thought of the mathematical absudity of travel
ing circular storms went TO refer tornadoes to the
action of travelling discharge Of electricity, and de-
tailed some difficulties he had met in getting his views
before the French Academy greatly to the amusement
81 his audience. There was no other entertainment
hst evening.
The attendance this morning at the sectional meet
hgs was scarcely less than On previous days.
MATHEMATICS AND PHYSICS.
Prof BAcBE called the section to order, and DIR. b.
A. Gould was appointed Chairman for the day.
Prof w. II. GILLESPIE of Schenectady then read q
paper the warped surfaces occurring in rosd excs
vstons and entertainments, illustrating it by neat
ysmes. The result of his investigation that the
ordinary prismodal formula is exactly and vigorously
correct for warped surfaces such as would ordinarily
in nature. In fact the plane surface of prism
ealy special case Of warped surface. This result
sO great practical value to engineers, showing that
= using the pTismodal formula they builded better
han they knew"
The second paper, by Prof j. LECoSTE of South
Carolina College, treated Of the alleged influence of
solar hight on the process Of combustion. Having re-
pested Dr. McKeevers experiment, on the burning Of
tapers with great and precautions against error
he found that solar light exercised no sensible specific
action on the rate Of combustion Prof Leconte pro-
ceeded 10 remark the influence of barOmetric pres
sure, and the temperature, upon the rate Of combus-
ION, which very decided. The presence of
aqueous vapor aso acts in retarding this rate. He
thought that the subject demanded careful expert.
nents, and be intended to pursue them during the
ensuing twelve months.
Prof. BAcHE thought that in this paper Of DR.. Le-
eente recognized the true inducve spirit He had
been charmed with the criticism of DR.. McKeever,
and Also with the ingenious, careful and thorough
mannerj (which Prof Leconte had conducted the ex-
periments be had SO modesty and clearly described.
The third paper was presented by Prof HAMILTON
L. SMITH of Kenyon College, Ohio lie gave brief
sketch Of his efforts to improve the construction Of
aehromatic telescopes TO diminish their expense
without diminishing their power. He adopts a form
bong ago suggested, of having the correcting lenses at
Che middle Of the tube and his Improvement consists
in the discovery that little gss, lens intro
duced just behind the eyepiece produces perfect
correction for the color Of the divergent pencils, e.
Of images not in the center of the field The correc
irons for spherical error and for the color of the CEN
trail pencil are produced by movements Of the lenses
at the middle of the tube The success of these i'm
provements has been marveously great.
Prof 5. ALEXANDER made a communication on
some peculiar relations Of the strsigh. line and special
curves lie prefsced his remarks by q statement Of
Me nature Of Zero not the absence of every
ding but only the absence Of the thing in question:
Zero Of matter is space, zero OF space surface,
Of light dark, and these not nothings but
something's, which illustrate that zeros may have
ratio to each other He then proceeded to discuss the
agebraca formation of higher equations, by the null
duplication of linear equations, and the geOinetrca in
terpretatinn Of these results.
The next paper, by DIR. j. H. GIBBoN, of the United |
States Mint, treated of the twenty fourcarat grains
and other modes Of expressing the neness Of the pre-
cious metals, and the quality Of jewery pearls, &c.
Like his previous paper, this was filled with interesting
historical anecdotes of the usage Of all early and
modern uncultivated nations. The accuracy of taking
selected seeds sanc ards had been tested at the
United States Mint, and shown to be very untrust-
worthy. The French system of decimal assay is used
in this country As TO modes of assay Dr. Gibbon |
gave q sketch of the usage from earliest Hebrew
times. The tOuchstone without acid and the touch
stone with acid the assay by fire and by solution,
ustd in various nations, were described in very pio-
turesque and lively manner DR.. Gibbon spoke es- |
pecisy Of the value Of the Hebrew writings for the
exact and precise notices which they give of all the
metullargc and coming practices, and commercial |
usages, not only Of the Hebrews but Of the neighbour
ing nations
Col G. G. FoRsHAY, of Texas read a paper on the |
phepome Of the Texas " norther." He spoke of |
The great raness region in the western portions Of the
United Slater and said that tbs plants of the cactus
In a
they abound there viii not be rain enough to cultivate
grain The norther usually begins in the morning.
. sudden, cool and dry wind Of great violence. The
thermometer frequently falls ~ degrees in 20 minutes.
The point at which the storm begns s visited ut the
commencement with dash Of rain lasting only fe
moments. The velocity of the wind is frequently 40
miles hour lasting for two three days. Col.
Eorshay considers il temporary violent trade
wind j. G., sudden doache of air from the high dry
southwest wind which is always blowing over that
country.
After some discussion concerning the periodicity of
orms and their tendency 10 repeat themselves at the
end Of q week, Prot. BAcHE read a paper upon the
determination Of the longitude Of Fernandina Amelia
Island Florida by the Exchange Of chronometers be.
tween Savannah and Fernandina. The incidental
results concerning personal equations, and the effect
of temperatures, &C., upon the chronometers, would
probably be more interesting than the mere longitude
result although even that is not without Interest, as
ne best charts differ nine miles in the longitude OF
that important island. Prof. Bache and his assistants
M Echott and Mr.. Boutelle, taking every possible
precaution against erior, made about 1000 obsetva-
lions. On comparison OF the observations OF Prof.
Bsche and Mr. Boutells, they could find no personal
equation which did not prove less than the probable
error That is the differences between their percep.
tons seemed 10 be wholly variable and accidental aud
independent OF any personal diierences OF eondon OF
power. But between Prof. Bache and Mr.. Schott
there a marked and constant difference OF six
tentbs Of second, and above the accidental va
risons. more regular result that the two sets
Of chronometers employed differed in their testimony,
hat "A al hetxy he