Maryland independent. [volume] (Port Tobacco, Md.) 1874-current, 1916-01-14
making A RECORD
Iiethods by Which a Phonograph
Disk Is Produced.
CATCHING The SOUND WAVES.

VI (itA4Nl H. SOOilG HRN GSs
They Are First imprisoned In Wax and
Then Transferred to a Negative In
Copper, and From This Master Mold
the Records Are Obtained.
The Edison phonograph, the graphic
phone type perfected by Bell and Tain
ter and the sramophone type By Ber-
liner are all based on substantially the
same principle. Sound waves set up In
the air By any sound are allowed 10
strike a delicately held diaphragm.
which vibrates under the impact Of the
sound waves Tile vibrations are made
to leave a record on q suitable me
dium. and this sound record IS used to
perform the inverse operation wheu it
Is required to reproduce recorded
sounds-thal Is. the record is made TO
vibrate sensitive diaphragm and set
up In the air particular waves. which
convey to the ear the impression Of
sound
The differences in the SYSTEMS are in
the way in which the vibrations are re
corded. The disk record, which lIade
the machine popular. was first manu-
facturcd in the United States in 1897
Improvements in the machine and in
the needles followed
To make sramophune record per
son sings before the mouth Of a horn.
the object Of which is to concentrate
the energy Of the sound waves upon
the recording diaphragm. Al the mar
row end Of the horn are the recording
sound box and the machine With its
attendant expert There is a screen
between singer and operator to guard
the secrets Of the sound box. On the
farther side of the screen is hori
zontal table carrying a wax tablet
rotated beneath the recording sound
box at Uniform speed. usually about
seyenty-six revolutions per minute. As
the table rotates it travels laterally a,
Uniform speed ana the wax tablet
Is thns caused 10 travei Slowly nnaer
the stationary recording ooN- Ine
sapphire cutting point Is lowered 50 %
as TO enter the wax three ana one-hali
TO Tour one-thousandths or an inch' ana
as tue hlaehlhe runs II cuts hhe splial
sruoFe' running from the euse 10 tnt
center Ane construction OIL tne souno
noA = secret as i the eohipositlon o'
Tue way 'apiet'
ne heAt s'ep IN 'he process + lne
'elfouue'ioh OF 'ne reeoru as u mega
1--WE ~ copper me wax Is uus'eu WIN
sraini'e "iit NofAeu mo tne sroofe'
WIN oauseF ufusn 10 h'aNe II -eiee
'ro-eohdueuNe' theh II Is lowered nit'
an eiectroiNtc oath OF copper salt soiu
tion- Inc wax IS kept IN CONTINUOUS
motion In the bath until the copper
shell is nine-tenths of a millimeter In
thickness.
This negative is a master, and from
/ this a few commercial samples can be
pressed to test the assI;,ss. rr,..s.zss.,,.s-
ord. The .,,ss,, ~, ,.t,srars no,roror
wish to r,sl-a ,ho,,sa,as 90 ao,,os
wit,5,,, ,,,t,n,, tha,, - -.
= -, ~ - a,,a,.,a.s -, -.
,sstar Il. 'a,',.., | 80 ,a,.a',.. ~, -
co,nnnsi,io, srn-n y,b;eh ',,,, n,o,l',,,., - mo,
49, l - - a,i, ~" ~, 80 ~
~ -, 'v - 80, ,, 1ea, eu.l,gt ~, 'iie''s ,
~ ~. 'osr..'ep ~, .ao.n 'unSe i, 'ue SAM, same
Wy lne 'oii's' s'ieii - 'nfi, paeAeu
y I pl''ss l,i'i.e oiie. llall uien N 'hicS'
nsSs oy so'uef'hs unuei pressure
Ihen tne MARK Is nickel plated on
Tue recorded SIDE III order to wear bet