THE TELEPHONE AND ITS INVENTOR. 



545 



regulator, or loose-contact mechanism, consisting of the spring g bear- 

 ing on the lever c cl, actuated by the elastic membrane o. 



The receiver in this figure consists of an electro-magnet, m, on a 

 sounding-board, with an armature, regulated by an adjustable spring, g, 

 pendulum-mounted, and " connected with a lever, i, which is as long as 

 possible, but light and broad." This expansion of the armature is for 

 the purpose of increasing its superficial contact with the air for the 

 propagation of sound-waves. The Reis armature, so equipped, is the 

 equivalent of the "diaphragm " in what is commonly called " the Bell 

 receiver," a form, however, which appears to have originated with 

 Elisha Gray. In the " Bell receiver " the diaphragm is an elastic, ex- 

 panded, circular armature. The Reis electro-magnetic receiver is thus 

 a complete and perfect anticipation of that of Yeates, of Dublin, in 

 1865, and of the later receiver of Gray or Bell. The function of all is 

 to move an elastically supported armature backward and forward, and 

 so throw it into vibrations corresponding to those imparted by the 

 sound-waves to the transmitting apparatus. 



Fig. 2 is copied from the " Prospectus " of Reis, dated August, 

 18G3, containing instructions to accompany the telephones constructed 

 for him, and sold by W. Albert, of Frankfort. The transmitter here 

 shown has been usually called the "box-instrument." In this type, 

 instead of a spring adjustment of the current-regulator or loose-con- 

 tact mechanism, as in Fig. 1, we have the angle-shaped " Hammer- 

 chen," as Reis called it, or little hammer, poised on the supports a b, 



Fig. 2. 



and resting by gravity on the strip of platinum-foil at the center of 

 the tympanum seen below. A little drop of mercury at b makes per- 

 fect electric communication between the little hammer and neighbor- 

 ing screw-cup. The elastic feature of this loose-contact arrangement 

 is confined to the animal or other membrane of the tympanum itself. 



vol.. xxiii. 35 



