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NATURE 



[Nov. 29, I ; 



As a good many of the specifications describing the 

 new improvements are not yet made public, we are rot at 

 liberty to describe minutely the various parts of the 

 instrument. We can, however, give the following outline 

 of its leading features :— 



(i) There is a brass cylinder on which the wax phone- 

 gram is placed. 



(2) A rocking holding arm, which carries what is 

 termed the " spectacle," containing the recording and re- 

 producing diaphragms, and which by means of a traveller 

 arm is made to engage two rotating screws — one called the 

 feeding screw, very finely threaded, which causes it to 

 travel slowly from left to right over the rapidly rotating 

 phonogram, and thus trace out a long spiral on its 

 surface ; the other, a coarser reversely-threaded screw. 



which enables it to be moved back more rapidly opposite 

 any required position on the phonogram. By means of a 

 screw-head attached to a turning bar with an arrange- 

 ment of cams, the rocking holding arm can be made to 

 engage either the feeding or reversing screw, or else lift 

 the diaphragm and its recording or reproducing needle 

 entirely off the surface of the phonogram. These back 

 and forward movements can be preferably made by a 

 treadle attached to either the turning bar or rocking arm, 

 leaving the hands free for other purposes. 



(3) Another very practically useful adjunct consists of a 

 projecting arm attached to the turning bar, by which the 

 operator when desiring to stop and think what he is going 

 to say next can completely disengage the diaphragm and 

 and its accompanying recording needle from the surface 



Showing reproducing diaphragm in pos'.tion, the operator listening through the tubes, and standing behind the instrument so as to allow it to be seen 



of the wax ; and if the pause is a long one, and he does not 

 desire to waste his phonogram, he can reverse the move- j 

 ment of the diaphragm until it is opposite the point on 

 the phonogram where he left off. By combinations of 

 arrangements of this sort, all the actions of an ordinary 

 writer, stopping to think, looking over, and even correcting 

 what he has written, can be imitated. 



(4) The arrangement by which a phonogram can be re- 

 moved and another replaced, simply consists in having one 

 of the centres on which the brass cylinder turns, attached 

 to a movable arm. 



(5) Though,theoretically,one diaphragm could effect both 

 record and reproduction, it is found that the same shape 

 of needle or style is unsuited for both purposes. Conse- 

 quently, there are two diaphragms, one a recorder and the 

 other a reproducer. 



The style of the recording diaphragm is made of such a 

 shape as to be more of the nature of a graving tool, while 

 that attached to the reproducing diaphragm is inclined at 

 an angle to the surface of the wax, and glides over its in- 

 dentations without destroying them. In front of the re- 

 cording style is placed the cutting-out tool, whose function 

 is somewhat analogous to the dibble of the gardener. It 

 not only prepares a furrow in the wax in which the record 

 can be made, but it also destroys any previous lecord. So 

 that the making of a fresh record and the effacing of a 

 previous one can proceed simultaneously. 



The use of tubes to the ear raises a point about which 



a good deal of misapprehension appears to exist. The 



machine at present is not intended for reproducing sounds 



with their original intensity, but rather for the perfect re- 



1 production of articulate speech and music. Many persons. 



