318 POPULAR SCIENCE MONTHLY 



were installed, but occasionally an editor would consider his time of 

 sufficient value to justify the increased outlay of $10 a year for a 

 ( second telephone.' 



Following the now famous experiments with his telephones at the 

 Centennial, Alexander Graham Bell had displaced the parchment or 

 membrane diaphragm with one of iron, and brought out the wooden 

 hand telephone to take the place of the oblong box, so inconvenient 

 for general use. Then, in December, 1877, a few long rubber-encased 

 hand telephones similar in form to the present receiver were sent out 

 to several exchanges as an experiment. On July 1, 1878, Mr. Coy 

 had 230 mahogany hand telephones, about 100 rubber hand telephones 



Fig. 23. 



and a dozen box telephones. But this rubber hand telephone did not 

 go into general use until the summer of 1878, and, in some exchanges, 

 never really supplanted the original wooden hand telephone, the earlier 

 magneto sets doing so. 



Meanwhile an improved form of the oblong box telephone, shown 

 in a previous chapter, was brought out in June, 1877, but met with 

 no favor, as it also required a table or a shelf for its support in a 

 horizontal position. In August, 1877, came the first of the oblong 

 box telephones remodeled so as to be fastened to the wall in a vertical 

 position (Fig. 23). The only telephone circuits in those days were 

 private and social lines, the first commercial exchange opening in 

 January, 1878, and users of projected private lines did not take kindly 

 to this innovation, preferring to have the more convenient hand tele- 

 phone which could so easily be shifted from lips to ear. And this was 

 the prevailing sentiment even after exchanges were in operation. Thus 

 this upright form of box telephone did not come into general use 

 until the winter of 1878-79, when it served only as part of a sub- 

 scriber's set. 



In the autumn of 1878, the parent Bell company brought out the 

 first of the many forms of magneto bell telephone sets. This early 

 type of wall set (Fig. 24) had the rubber-encased hand telephone 

 hung from a hook projecting through the door on the front of the 

 box. The attaching of two hand telephones to the magneto to serve 



