New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1869-07-15
SCIENTIFIC NOTES.

OHANGES IN FEMALE ANINAL9.-A CORE
spondent Of The A'serican Naturalist states that doe
was recently shot Minneapolis, Mimi, carrying
beautiful pair of anters each with four branches and
whether this is fact in natural history
which the editors reply that they have heard OF
female deer assuming the character OF male before;
but II is wen established fact that female birds living
extent the habits Of the male In the Museum Of the
PEABODY Academy OF Science at Salem Mass, there Is
10 years changed her dull female plumage for the bright
plumage and full trail Of the male bird n. Vckery,
TaXiaermist O Lynn Mass, has the specimen mounted
CRACKING OF CCLLoDION FILMs-At a late
meeting OF the London Photographic Society the Chair.
man. Mr. ]. Glalsher, y. r. s.. remarked that he had
often regretted that ladies seldom attended the meet
ings Of the Society He glad to see two present at
that meeting and one Of them. Mrs Cameron, desired
say few words 70 the members
Mrs Cameron said she wished to obtain the opinion Of
members as to the cause OF cracking IN the MIN OF her
negatives. She produced large negative Of Sir John
many Others taken by her, covered with honey-comb
like cracks. The eOlOdiOn film appeared 70 be cracked
under the yarnlSh, the a'teo beng intact During
the last six years she had taken about COO mega
tiyes and during the last two years about As
of ess sed the ea long ns and place
animation Of OF the negatives alluded 70 followed,
the Of which it pointed out that the cracks
through the yarnh as well as eolodlOn, and that
they often resulted from the Of S9hnee varnish
Mr.. Thomas said cracks IN the cOilOdiOn film had
fortunately been occasionally seen ever since the intro
dueton Of the cOOdon process no matter what coodon
what varnh had been used, without the fault being
due 70 either but rather 70 the lncOnpau1ty OF TIE
same two samples when in conjunction. Changes in
effect. photographer OF considerable eminence and
large experience had recently told him that he
cracked, while similar negatives put away
pateboxes did He believed that where the colo
dion made thick. with view 70 secure dense
tves the tendency crack increased the thickness
OF the film affecting, Of course, s cOntractbty, and
duced with the materials and apparently under the
same circumstances cracking, while others remained
Mr. Blanchard said az Mrs. Cameron resided at FRESH
water, her residence would be subjected sometimes 70
linda hru rim Tuucl IN
moisture and IL this, he had doubt the cracks
due The best mode Of preventing the effect OF damp
pack the negayesn paper instead Of keeping them
in platebOXes. Referring 70 Mrs CamerOns negatives,
the appearance justified her impression that the
collOdiOn only and not the varnsh which cracked
This he would demonstrate by rubbing the surface with
little SCOT. would be seen that by this operation no
had at once filed the cracks with SCOT, and made tho
negative capable Of being printed without showing
After Mrs Cameron had expressed thanks for this hint
Mr. Hooper suggested that OF the Of cracking
moisture the plate from the breath OF the opera
which condensed on large plates during the process
Mr. Dameyer pointed out that some kinds OF glass IN
derwent a change, technically called sweating"
tain oxidation appeared the surface caused by
Of alkal In the manufacture; II was impossible TO
wipe such glass clean, and the presence OF this
oxidation causing dampness, might be the probable
part Of acid 70 four parts OF water.
due 70 moisture and mentioned that owing TO the burst
ing OF steamppe IN his establishment, the walls had
become damp on one occasion, when the MINIS OF the
Mr. Howard expressed the opinion that moisture was
the Of the difficulty. He attached considerable
Importance 10 warming the plate thoroughly before
vanishing and after vanishing 10 drive OF all traces Of
alcohol
Mr.. Elliot thought that plates should be wrapped in
peper, and suggested that the paper should DO made
waterproof with gutta boiled ia HDseed Oil, or
with some similar substance.
PHOTOGRAPHIC AID IN SURvEYING.-The fol-
lowing extract from the report Of Regnaul FiEesu
and Abbade the French Academy of Sciences upon
ingenious invention by the late Mr. A. Chevaler which,
Is destined to become Of great service in the art Of
yeying:
When Daguerre first employed the camera for the pur
pose OF nKng images upon metal plate, Arago at
suggested that topography might borrow from photogra
this great physicist rise divers projects 70 bring
about the solution Of the problem and FIVE years later
NJ Martens showed how II was possible 10 FIX upon the
surface Of cylinder succession OF images received
through q narrow Slit by means OF movable lens. In
this mapneT NJ Garela, EngneerinCbief OF Mines pro
eeeded TO perfect the instrument in such way as 70
der IL possible that images might be taken on plane
surface and that the whole tour OF the horizon might be
secured The details OF the instrument exceedingly
Ingenious but when IL desired 70 construct plan,
long calculations and deductions were necessary causing
delay and giving rise 10 the possibility OF errors
Seventeen years after tho invention OF Daguerre Mr. A.
Chevaer stated In precise terms the problem 10 be
establishing the fact that in order to obtain plan
upon paper was necessary construct AZ each station
special prOtTacOr formed DhOOgraphcaY bY the whole