Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1911-08-02
A ROPE OF water.
RertheIot'S Test That Showed Its
Tensile Strength.
THE COHESION OF MATTER.
Perfect Planes Of Metal or Glass When
Brought Into Contact Will Adhere to
One Another as Though They Were
Glued Together.

= One Another as Though They Were
Glued Together.
1t is we'll known that liquids are
among the least compressible Of sub.
stances; this in spite Of the fact that
they have the property Of conforming
to any shape Of vessel or of yielding
to any forces. no matter how small.
which tend to change only their shape.
Thus, to squeeze water into nine
tenths Of it's volume under ordinary
conditions would require pressure
of no less than 5000 atmospheres. or
$4,000 pounds. to the square inch.
This property of being almost incom'
preSsibe is best illustrated perhaps
by an experiment tried centuries ago.
wherein an attempt was made to com
press water by filing leaden shell
with it and then. after closing. ham
mering and squeezing the shell. The
,nly effect Of the tremendous pres
surcs produced in this way was to
cause the water to penetrate the mi
mute pores of the lead and exude in
drops like perSpiration on the outer
surface of the shell. The same effect
WAS found for silver shell.
But. while it is familiar fact that
liquids will resist an enormous force OF
compression. the companion fact that
they are also capable Of withstanding
tension is not so generally known. Al
first sight this statement may appear
ridiculous. When water may be so
readily dipped from a pail or poured
from one vessel to another, how can
it be capable of withstanding tension?
If. however. we prevent change OF
form we find that pure water Is capa-
bic Of bearing fifty atmospheres OF ten
sion. or $50 pounds to the square inch
If it was possible. then. to utilize this
property by making rope of water
we should find it capable Of sustaining
good fraction Of the weight tha
could be horne by an ordinary rope OF
the same size But it must be admit
ted that the task Of making rope out
of such material would be rather diff.
ficult. to say the least. Notwithstanding
the fact that it possesses this desirable
property of tensile strength. Because
Of it's inability to resist deformln:
force it would have to be inclosed in a
tube: but. while it would here be In
condition to withstand compression, as
from piston in the tube, any attempt
at "stretching" the liquid in this way
would simply result in pulling away
the piston from the water surface.
However, this tensile strength was
actually found by Berthelot in the fol-
lowing way: \ strong glass tube sealed
at one end and drawn out very fine at
the other was filled nearly full Of wa
ter and then closed The tube was then
cant iously heated until the water had
expanded and completely filed it, 1t
was then slowly and carefully cooled
back to its >rigina! temperature, when
it was found that the water had moi
contracted. hut still filed the tube.
1t is almost a universal law that
small extension in volume OF a body
requires the same magnitude of force
TO produce it as to cause similar
amount of compression. the forces. how
ever, being tension in one case anu
compression in the other. With this
law in mind it is readily seen that the
water that now fills the tube must he
under tension. since previously at the
same Temperature it did not quite ill
the tube-that is. it has actually been
stretched O: expanded beyond its nor
NAL volume for this temperature. and
from our knowledge of the forces that
would be required to produce the cor"
responding compression we can figure
out what tbs tension must be.
The ultimate particles or molecules
q; natter we believe TO be held to-
rcthrr rs powerful forces. known va
rio,,sly rs cohesion or adhesion. but
being in any case forces Of attraction.
and these f.'rrcS tend to prevent any
c:,nnSicn os the matter, be it SONG or
,iou:G II night be thought that these
.U.', tS " ". tEtSc wv UEVlSS Ia SoH'
t: to :1It:c to each other. but par
ii, rs have to be so near together to
ii. acted u|rrn By them that it Is dlt'
t;,:': to br::.:: hoG:es int, such close
.u::a.t thu, an Arrreriab!c "rea ut
one is within tbs di>t:nre o: I'N' "tH'r
However. twD r!r::': pie e> 1T lead
can readily y" pressed =" '''''s':H 10
Ccthpr that they wi! :t'''r'" "":.
set ue ,r,r"r cube; W" on g I":''
with such tive faces thai "';:'' y {: "
en- CT them were ,::'r'' co. II -" =
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50 wei! that tie "..:,''.' '"; :! / :
f,or the to-, -: ~ '''>t e.
am,,,p j., furnished - "'r> g: I:
teal e.: IS ::.:.!!::,'e -: .:.:';'
worked SO l':::" -: ~!
cct!"r they vii! IS r"'n''' -
some other $50 "> ii; 'EiS T. -
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