New-York daily tribune., 1855-08-20

stead knew OF DO lDttAICt OF kItotsl Po~Ntf
the great explosion Of Brescia, where two miilons OF
pounds of powder exploded, that equaled his.
Iron water pipes were broken four or hye feet nnde
proun6 IL the New Haven tornado Of 1899, pleoe
Of bureau was carried half mile and ounf sticking
into ham ha,1nc penetrated through thick plank
Feati. r. hsve been stripped on OF iowls anu woman
uashinr found herself and her tub, with rs water IN
the celsr while some II the clothes sne was wanlls
ve,s fonnd beyond West Rock, distance OF two
nils Fowls have been known 10 DC stripped OF
ther feathers in such tornadoes'
Prof MAHAs said thst sappers and miners had
rule tia, the lateral force Of an explosion would ae
sroy the works at three four times the distance 70
,te suace and the downward force would do the same
to tSree-qusrters the dztsnce Of the surface
Prof HESRr said that TIE shoes were not blown on
the horses feet but that the horses were bowu away
from the shoes Iron has specific gravity of about
seven tines that of an srimal BODY.
Mr.. WV c. REDFIELD saw no satisfsct ny evidence
Of a vacuum. Causes often mistaken but he hsa
never found any clear evidence Of vacuum though
SO much had been attributed to such a cause.
Prof BR,ISARD thought many phenomena rescui-
bled those Of electricity stripping doors OF theH
hinges and birds Of their feathers.
Prof. LOOMS thought the ndentaton in the ground
was analogous to the process for submarine explosions
only as the resistance OF water Is greater than air the
force is proporonay greater. As to feathers the oss
Of en- has been attributed TO vacuum bat tow SUD
denly exposed to vacuum loees 10 eatheIs; froL
LootIis pui live fowl into a gun OF tSoinch bore,
win sixth of a chaIge OF powder, anu aimed az
zenith /, cane down deIuded of feathers aud mangltd
by ing more powder tnan was necessary
P,of JoHSsoS thought there was an anelogy Oe-
tween the indentaiion Of gunpowder here and that
often exhibited by more violent ful nina es. Two
ourcts of Illuminating mercury viii periorae an lnoh
plank when there is nothing TO oppose IN any drec
prof RopGERs thought that there never could be
any condensation of cir by explosion without subse-
quent rareisction and that vacuum payei neces-
sary part of the phenomena of tomatoes
Judge OSBORS gave some curious circumstances
ahout sand. blasting. The hole is not 10 Oe entirely
flec ard tie SAND sbould be dry. Dry chat may De
substtu I'd for sand, and would be better tnan wet
sane. At an explosion he noticed thet those wno
were frihcst from the explosion were thrown iurthest
and least Injured. Tie nearer ones were moved little
but denuded and maDkiod.
Prof. HENRY read paper on the modes OF testing
building materials and account Of the marbles used
at Washington. He had been appointed on a COM
r,to to test the materials offered for the extension OF
| the CAPITOL at Wasbin ston. The committee had to
! take iufo consideration many minute sources oil
disiutegratiou, such as that every dash OF lightning
produced an anpreciebe amount OF nitric a III,
which dlffussd IN ram water acted 90 the caroon-
ate OF lime aud the action OF Gust carried oy te "ind
against the building. The committee subjected 5pecl
mel 10 actual freeing aud ailer several experiments
Good uaetod was obtained. Ii was found that IN ten
thousend wears one inch would be worn from the blocks
by tie action OF frost. Blocks OF l. inch cube were
subjected 10 pressure AID thin plates OF lead, as ha
been the case in O experiments, being Introduced
10 eouaize any inequalities which might occur IN the
sufaces But upon experiment 1t was found that wnlle
one of these cubes would sustain 10000 p0u,ds wth-
out the lead plates II woId sustain only 3OOOO with
Them They had therefore to invent machine 10 cut the
side of the block perfectly parallel whenl was found
that II marble which chosen for the Cepi OIL nom
| n quarry in Lee Massachusetts,, would sustain about
% OOO rounds to the square iucn The manner OF IT'S
brenkifg was peculiar. Wi'h the lead plates inter-
posed The sides which free, first gave way eav-
ing the pressure two cones whose bases JOtded ue
MA es and whose apcxcs met each other and that they
then Welded with comparative ease. This marble
absorbed water by capillary attraction, and IN cOm-
! mon with other marbles was pfrmeaDle TO gases
! Soon after tie worAuen commenced placing "
/ in The walls il exhibited O brownsh dlscoloiaton
although no trace OF 1t appeared While the boc<s
umeir ed in the stOnecuttcrs yard. vG1ety OF ex-
perinens were made with view 10 ascertain the
cause of this phenomena, and II was finally concdded
to ie cue TO the previous absorption by the marble OF
water holding in solution organ'c mstter, toge her
with the absorption of another portion OF water from
the To illustrate the process, he supposed
! fine capillary tube with its lower end immersed IN
| water whose internal diameter sufficiently small
TO allow the liquid to rise to The top be exposed 70
the atmosphere. Evaporation would dke place a. the
upper surface of the column, and new portions OF
water would be Drawn up 10 supply the loss, and II
this process were continued any material which might
be contained ia the would be- found deposited at
the top OF tie tube, the point of evaporation. II,
however the lower portion Of the tube we're not fur
Ished with a supply of water, The evaporation a. the
top would not ake place and the deposition of foreign
mott.r would not be exhibited, even nough the tube
itself we're filed with water impres et with I'M
puriies. The pores Of the marble, so long as the
blocks remained III the yGId, were in this last condition,
but when The same b ocks were placed in the wall Of
the buiolUg the water absorbed from the mortar at
the interior surface gave the supply OF liquid necesay
to carry the cOorng materials to The Xeror surace
and fleroeif IuDutlg of the The
| cause Of the phenomenon being known, aIemedy was
reaciy suggested; the interior surface OF the
coated with asphsitum, rendering Il lmperyous 20 the
/ moisture of the mortar, and the discoOratOn was
/ gradually disappearing In series OF experiments
made ten years ego he had showD that the al rae
ton al The particles fOt each other Of substance
liquid form was great that OF the same subs ance
ia solid form. Consequently the dstl1cto1 bet" cen
lquiCy end scidity did uOl sst difference in the
attn scive power occaioLed directly by the repul-on
Of heat: but it depended upon the perfect mobility OF
the atoms or a lateral cohesion. He nigh explain tins
by assuming 40 ncipient capitalization of atoms into
m0..c5cs and soer the first elect OF heat as thai
OF hoGking down these crystals and PERM ting each
atom 70 move freely around every other. When this
crystalline arrangement was perfect, and no lateral
motion allowed IN the atoms, the BODY might be
| GeLOminafcd Teffectly rigid. q had approx mae'y
az exsmple Of this in c3st steel IN which slipping
took place of the parts on each Otoer, no material
elougstiOn Of the mass and when rupture was pro-
duced by a tensile foroe, a rod OF this msteral
/ broken with tranyerse fracture OF the size
that of tie original section Of the bar. In this case
every atom was separated at once from the oher, aud
the breaking weight might be considered measure
of the attraction OF cohesion OF the atoms Of the metal
/ The effect, however, was quite different when We
attempted 10 pull apart a rod OF lead. The atoms
or molecules slipped upon each other. The rod
Was increased IN length and diminished IN thickness
until a separation w8s produced. Instead Of lead we
might stll softer materials such wax and putty