OF ARTS AND SCIENCES. 



103 



inspection of Tables IX. to XVI. and Figures 9 to 14. We have 

 still to determine whether the same peculiarity would be observed 

 with other modes of mounting the electrodes. 



Besides the foregoing results, we have made a determination of the 

 actual strength of the working currents employed on telephone lines. 

 The values previously obtained in the Laboratory had been ascertained 

 from experiments on very short experimental circuits. But through 

 the courtesy of the Long Distance Telephone Company, we were able 

 to put our measuring apparatus in circuit both with the city telephone 

 lines and with one of the long lines to New York. 



Several interesting results were thus reached, as shown in Table 

 XVII. The first column gives the name of the transmitter employed, 

 the second the nature of the sound transmitted, the third the location 

 of the transmitter, the fourth the strength of the telephone current in 

 milliamperes. The length of the line from 95 Milk Street to the 

 Institute was about two miles ; that of the line to New York was two 

 hundred and sixty miles. 



TABLE XVir. 



The speakers were Dr. W. W. .Jacques of Boston and Mr. F. A. 

 Pickernell of New Y^'ork. who kindly aided us in our work. They 

 are both experts in the use of the telephone, and accustomed to 

 work with each other. The pitch, as well as the loudness of the 

 sounds used, was kept as nearly as possible the same. The vocal 

 sounds transmitted Were spoken in a very loud tone, and close to 

 the transmitter. 



