Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1881-01-15
A FUsIEa DISK.

The scientific papers, among them the
London Engineer, the american NGHu-
ftefarer, and the illustrated Scientific Neirs,
have been aroused TO an unusual spasm OF
speculative energy by certain little instru-
ment, styled the fusing disk, IN use IN large
iron aud steel establishments IN PittsbUrg,
Pa, whose operation raises new and diff
C at question IN molecular physics that it
Will REQUIRE accurate experiments TO solve.
The fusing disk is described as an instru-
ment for cuttiug cold steel by current Of
air, and although at first glance esembling
the cold saw. Eas nothing IN common with 1t
inits mode of operation. iE Is, of course,
familiar fact among en- 1iueers that disk
II soft iron revolving at high velocity
,glll sever 4 bar Of the hardest steel in a
few seconds. provided that the contact and
pressure are properly regulated, The fus-
ing disk, although 1T might be mistaken for
ne cold saw M external appearance, oper-
ates . pom an altogether different principle,
and one whose efficiency rs not readily ex-
blamed from hitherto aseertained laws
respecting the fusion of metals. There is
no actual contact between toe edge Of the
disk and the bar TO be severed, and the
work is done entirely BY q lacal fusion Of
the latter without material elevation of the
temperature of the disk, which consists of
a thin circle of soft steel almost 81 feet in
diameter. making $50 revolutions minute
equivalent to 49, 3 l4l592z230) an an
gular velocity Of 2535 9Sl56 feet. The bar
to be cut must ZEE round. and, firmly Sc
cured in front of the disk, revolved at
about the rate of aboat 200 revolutions per
minute in the same direction. Thus ar
y 81 Il I4-. s,E
steel ] inches IN diameter may be sew
cred in from . to- 10 seconds by fusion.
The groove fused IA the bar as the disk
advances IS usually about one and half
the actual thickness Of the disk. and its
bottom Is always m advance Of the margin
about the same distance. Ii the bar is
not in revolution ths disk cuts its way
through after the manner Of a cold saw,
and the debris which drops from the in
csion is finely divided IRON oxide ;
while on the other maud when the bar is
In motion the dropplngs consist of small
globules Of metallic iron, thus showing
that molecular tension Is the only agent
concerned in the work. The puzzline
question, il hear IS 20 be regarded as the
agent Of fusion, Is to explain e generation
of heat sufficient to fuse bar Of steel IN
TWO 20 ten sScoluS % ttlS simple rGFOlQ-
ton IN the same direction. at no extraor.
binary velocity, Of the fusing disk and the
contiguous bar. The disk never becomes
sensibly heated IN the operation, and while
the ends Of the bar are perceptibly
raised in temperature the molten meta
that drops from the cut though sensibly
fluid in its texture, can be caught in the
palm of the naked hand of the operator
without detecting any rise that is in the
least incouvenient. It viii be obvious
therefore, that there Is q question OF mole
cular physics raised by this simple inven
tion which cannot be solved by reference
to hitherto asesrtained laws OF physics
Engineers and physicists in the journals
named have exhausted all the received doe
trines of occiuded heat, molecular tension
etc. in trying to account for this remark
able phenomenon, butit has not apparently
occurred to any of the parties to the dis
cussion that the probable cause OF th'
fusion is to be sought in the generation o
powerful electrical current by the revo
luton of the disk and bar in the same d.
rection. and the foundation of a voltsi'
arc at the point of fusion, producing intens'
local molecular tension.