318 SEC 10. ELECTRICITY. 



1625. Relay for the above (with suspended magnets). 



Employed by Siemens in 1855 in the first experiments made to employ 

 short alternating currents of equal duration for production of Morse writing 

 with aid of a polarised relay. 



1626. Mile Resistance, with steel; Siemens, 1854. 



1626a. Mile Resistance. 



1627. Original Colour-writer of John in Praag, 1854. 



1628. Relay with suspended magnets and double coils for 

 conversation. Erichsen and Siemens, 1854. Patented in Prussia, 

 with resistance scale divided according to miles of copper wire, 

 1"' diameter. As made by Siemens since 1848. 



1629. Polarized Relay, with a horse-shoe electro-magnet 

 aud steel keeper. Siemens, 1855. This form is still in use. 



1630. Induction Coil. 



1631. Induction Key. 



1632. Apparatus System for submarine conduction. Sie- 

 mens. Constructed for the Red Sea Telegraph Cable. 



1633. Back Current Discharger for submarine conduction. 

 Siemens, 1857. Used first in the Red Sea. 



1634. Colour-writer by Siemens. First construction. A 

 little colour arm, fastened on a universal joint, dips in an open 

 reservoir of adjustable level. Patented in England in 1862. 



1635. Hair Needle Galvanoscope of Siemens, 1869. 



1635a. " Edison's Electric Pen," and " Autographic 

 Press." Thos. D. Clare. 



This pen consists of a small electro-magnetic engine on the top of a holder, 

 which is used as a pen, and works a needle which pierces the paper, making 

 5,000 to 6,000 fine holes per minute, so that in writing such is the rapidity of 

 the motion of the needle that the point does not drag or tear the paper. 



The pierced paper or " stencil " is placed in a frame, and an inked roller is 

 passed over, which fills the fine perforations with ink. A sheet of paper 

 is then placed below the written paper or stencil, and the roller is again passed 

 over once or twice, when a perfect fac-simile is obtained. 



These fac-similes can be produced at the rate of four to six per minute, and 

 one writing or stencil will suffice to print 1,000 copies. 



1652. Electric Telegraph, original apparatus as it was made 

 under the direction of its original discoverer, Th. Sommering, in 

 Miinchen, 1809. K. Sommering, Frankfort. 



1653. The Volta's File, then used for the above, together 

 with the 10 original silver, and 10 original zinc plates. 



K. Sommering, Frankfort. 



