''TK 





us 



* s 



-^.^- 



Figure 8. — Another Page of the Plans Shown in Figure 7. The experimental Graphophone 

 built from these plans is in the U. S. National Museum (cat. no. 287665). 



heads. Later, when the complete models were Iniilt, 

 most of them feattired vertical turntables. 



An interesting exception has a horizontal 7-inch 

 turntable (see figs. 7 and 8). This machine, although 

 made in 1886, is a duplicate of one made earlier but 

 taken to Europe by Chichester Bell. Tainter was 

 granted U. S. patent 385886 for it on July 10, 1888. 



The playing arm is rigid, e.xcept for a pivoted verti- 

 cal motion of 90 degrees to allow removal of the 

 record or a return to starting position. While record- 

 ing or playing, the record not only rotated, but moved 

 lateralK- under the stylus, which thus described a 

 spiral, recording 150 grooves to the inch. 



The Bell and Tainter records, preserved at the 

 Smithsonian, are both of the lateral cut and "hill-and- 

 dalc" types. Edison for many years used the "hill- 

 and-dale" method with both cylinder and di.sc rec- 

 ords, and Emile Berliner is credited with the invention 

 of the lateral cut Gramophone record in 1887. The 



Volta associates, however, had Ijeen experimenting 

 with i)oth types, as early as 1881, as is shown by the 

 following quotation from Tainter: ' 



The record on the electro-type in the .Smithsonian package 

 is of the other form, where the vibrations arc impressed 

 parallel to the surface of the recording material, as was done 

 in the old .Scott Phonautograph of 1857, thus forming a 

 groove of uniform depth, but of wavy character, in which the 

 sides of the groove act upon the tracing point instead of the 

 bottom, as is the case in the vertical type. This form we 

 named the zig-zag form, and referred to it in that way in our 

 notes. Its important advantage in guiding the reproducing 

 needle 1 first called attention to in the note on p. g-N'ol 1- 

 Home Xotes on March 29-1881, and endeavored to use it 

 in my early work, but encountered so much difficulty in 

 getting a form of reproducer that would work with the soft 

 wax records without tearing the groove, we used the hill 

 and vallev type of record more often than the other. 



» Tainter, op. al. (footnote 1), pp. 28, 29. 



PAPER 5: PHONOGRAPH AT ALEXANDER GRAHAM BELL's VOLTA LABORATORY 



77 



