THE GRAMOPHONE EEDDIE. 217 



true reproduction of the original selection ; if, for instance, the record 

 is rotated faster, the sound waves set up by the reproducing dia- 

 phragm will be produced at a higher speed than that at which 

 the corresponding sound waves fell upon the recording diaphragm. 

 The greater the frequency of the sound waves the higher the note, so 

 that a record, if pla3^ed too fast, is pitched in a higher key, and a bass 

 solo can be reproduced in a shrieking soprano. 



The sound box went through a series of improvements, the object 

 of the inventors being to render the diaphragm as sensitive as pos- 

 sible either to the sound waves of the selection being recorded or to 

 the vibrations transmitted to it from the record disk, as the case 

 might be. The diaphragm is now lightly held at its edges by hollow 

 rubber gaskets, the fulcrum of the needle connecting the diaphragm 

 to the needle point is formed by knife edges, and its movements are 

 controlled by delicate springs. The standard sound box of to-day is 

 a very different thing from the early patterns shown in figures 1 

 and 8. 



Improvements were further made in the means of conveying the 

 sounds recreated in the sound box to the ear of the auditor. The old 

 ear tubes had disappeared to give place to a small horn, to the narrow 

 end of which the sound box was attached. As the popularity of the 

 gramophone grew, the public wanted more sound for its money, and 

 accordingly the size of the amplifying horn was increased. The 

 increased weight of the horn necessitated that a special bracket should 

 be provided to carry it, and the horn was accordingly balanced with 

 just sufficient weight on the sound-box end to keep the needle well in 

 contact with the record. Thus the machine remained for a time, but 

 in this form it did not satisfy its patrons, for it did not do all that 

 they thought might be expected of it. It was found in practice that 

 the turntable often did not revolve absolutely horizontally, that the 

 record disks were sometimes not absolutely flat, and that the central 

 hole was in reality but seldom accurately in the center of the disk. 

 Owing to the rise and fall of the record as it rotated, the end of the 

 amplifying horn also had to rise and fall, and owing to the eccen- 

 tricity of the hole in the middle, the sound-box end of the horn was 

 continually approaching and receding from the center of the record, 

 as it folloAved the sound line. In other words, the needle as it fol- 

 lowed its path along the sound groove, in addition to transmitting 

 the proper vibrations to the diaphragm, had also to move the whole 

 mass of the amplifying horn. This had two injurious effects; it 

 impaired the reproduction, and it wore out the record. 



The next step was to remove the amplifying horn to a short dis- 

 tance from the sound box and to carry it upon a rigid bracket on the 

 cabinet of the instrument, the sound box being connected to the small 

 end of the horn by a piece of tubing, which allowed the sound box to 



