New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1874-07-27
iss tJf carrying on those physical researches which
are intimately allied to their own science.

THE FLUoREsCENCE OF AMBER.-Dr. Labert OF
Breslau states that he has lately received colec-
ton of beautiful pieces of amber from Sicily and'
on comparison with the amber from the Baitic' was
struck with the great difference OF Color ana
especially the frequency of contrasts between the
surface aud the inuor color OF the pieces Follow
ing in the track of Brewster Herschcl, and Stokes,
Dr. Labert applied the proper tests to his amber ana
easily determined that both the sicilian and the
Baltic specimens notably exhibited the weii-known
phenomena Of fuorescence. Two pieces OF amber
which ON the surface exhibited q beautlful Diue
color showed yeowish red color when yleWeed
from the side but the phenomena seems 10 ne sun
iect to slight variations each separate piece OF
amber The fiuorescence is much more DECIDED IN
fine Scilian specimens than in those from the Balc
lie suggests connection with TINS SUBJECT that III
il well worthy of consideration whether Ill the
neghboThood Of Sicily there he not sunken center
of amber @ is supposed TO have been the case IN the
Baltic Sea.
UYDROGENoUs PALLADIUM.-The combination
of hydrogen with palladium. first discovered by
Graham and termed by HIM occlusion has been
generally supposed to indicate the formation OF
true alloy between the metals palladium and hydro
genum. This opinion was stated by Graham VINO
proved that the density of palladium when 1t con-
ccals from eight to nine hundred volumes or hyuro-
gen within itself is sensbly inferior to that OF the
pure metal. while its tenacty and electric conduc-
tlNltY Northumberland
This subject has been lately investigated by Messrs
| Troost and Hautefeuille, who have shown that the
phenomenon is more complex than has hitherto been
supposed: that in fact palladium forms with hydro
| gen definite compound whose formula is two MOLE
cules of the former and one of the latter Inns com
bnatOn itself formed can then dissolve bSulo-
! cen gas after the manner of platinum and IN
! quantity variable with Its physical state' Inns
property of the new compound expalhs tnf M nv
! ence between the numerical results obtained py
| Graham according as he employed palladium wire OF
spongy palladium. This Hydrocarbons palladium
together with certain similar combinations OF pots-
SUM and sodium with hydrogen forms a series
parallel TO that combination of copper with hydrogen
] called the bydride OF copper by Wurtz'
THE THEORY OF THE USES OF TIE SURVEYORS
LTvE1.-Prof Wittsteiu states that if one imagines
| = leyelipg to be conducted along the ocean level
| from the pole of the earth to some point on the
equator then, in consequence OF the method accord
| ing to which the level ordinarily used, the value
of the difference in altitude of the two ends OF the
given line would be exactly zero. To this Helmert
| adds that the conclusion can only be correct when
we neglect the unequal curvature of the various
points of the level surface as we proceed from the
pole to the equator, since Witseins CONCLUSION GER
tainly involves the assumption that the level or
horizontal plane is tangent to perfectly spherical
surface Oudemans of Batavia has taken up the
ouestion at this point and investigates the amount
of the accumulated error that would result from the
| assumption which Hclmert has correctly shown TO
be involved in Wlttstein'S statement lie cOhciuHes
that if the average distance between two successive
stations in the of the levellng operation ne
COO feet then the of all the possible errors arising
| from this source will amount to only l-5OJOth part
Of an inch in the entire quadrant OF inc eaIt CT
cum ference, but will amount TO three feet II tne
average distance between the successive stations De
so great twenty miles. In either case the error
| would he inappreciable IN comparison Win tAOse
! arising from other causes.
TIE HEIIoPICToR.-Jh HeliopictoT is the name
given by Dr. Stein to q simple apparatus devised by
him. and intended to expedite the Photographic
processes necessary in field operations whether for
scienifc or artistic purposes but especially the for
mer. His apparatus he also thinks applicable to
10 the investigations of physicians with the micro
SCOPE opthalmascOpe, etc.; he suggests, also, It's
special application TO the observation OF the transit
OF Venus. The apparatus consists essentially OF a
thin box that can be attached firmly to the eve end
OF a telescope, and when III that position the front
side of this box is composed of plain glass the back
OF which is sensitzed for the reception OF the image
TO be photographed. The back of the box is closely
sealed az also the sides, that no extraneoue light
can enter Between the sensitized plate and the
metallic back is a shallow space, sulhclent, however
TO contain the liquid that would I'LL the bath IL the
ordinary Photographic dark room. DR.. Stem pro-
poses after the seDsitized plate has been acted on,
10 pour unto this space by suitable funnel The
liquid necessary in order to fix the PHOTOGRAPHIC
image: in other words toe box is both camera and
dark room combined, all the critical Photographic
| operations being performed without removing the
sensitized plate from the box. Ihe eonpactness oil
! this arrangement evidently recommends II strongly
TO travellers aud it has been stated thai d. Stems
invention will be adopted by the German observers
| Of the transit OF Venus.
| THE FRENCH MUSEUM OF PHYSICAL AND Me-
! CuANICAL SCIENCE.-The establishment of the
Conservative des Arts ct Meters its origin 10
the ilustrious Vaucanson, Inspector of Factories III
the reign of Louis XVIII, and this magnificent edu-
cational establishment furnishes some details inter
estng to those who in this country have TO teach
| the experimental and mechanical sciences. The
total number of professors employed by the Con
seryatoire is fourteen, and the smallest number OF
lectures given annually by any professor is 4O
the number of persons who attend each lecture IS
| about 2i0 Originally intended a collection of
machines instruments, and tools for the instruction
of workmen it subsequently authorized to extend
its sphere TO all works of art and science. The sys
fem of lectures now carried began in 1920, in
| sequence of IA royal decree OF the previous year
In to that time instruction had been given only 10y
sight as it WERE by allowing the public almost free
| access TO the immense collection OF machines
models tools, drawings, books &c. The instruction
is free to ALL without any condition for admission or
| any examination. To the honor of the worklnen,
who form a large majority of the 100000 attendants
ON the lectures il mustb said that more attentive
audience cannot be found. Never does the slightest
disorder arise and even during the unhappy events
attending the recent Franco-German war. the Con-
servatoire was always respected and underwent no
disturbance or INVASION.
ARTEsIAN WELLs.-The irregulaTity of the flow
in artesian wells has been studied of late by Judge
Caton who has presented paper on this subject to
the Academy of Sciences of Chicago in which he
adduces some interesting phenomena, and very
truly states that it is necessary to explain these
in their details i'm order that shall