326 SEC. 10. ELECTRICITY. 



not liable to be interrupted by the demagnetization of the needles, which so 

 frequently occurs in needle telegraphs of the ordinary construction. 



Extract from the Handbook of Telegraphy, by R. E. Culley, Engineer-in- 

 chief of Telegraphs to the Post Office, 5th edition, pages 199, 200 : 



" The greatest improvement which has been made in the needle instrument 

 is the introduction of an induced magnet of soft iron for the needle in place 

 of the permanent steel magnet." 



1704. Instrument for sending double-curb signals into sub- 

 marine cables. Sir William Thomson. 



This instrument was constructed in 1858, but not completed in time for 

 trial on the transatlantic cable before its failure in the September of that 

 year. 



1705. Electro-magnet Relay for reaction produced, by the 

 magnetism emanating without regulation. Extremely rapid, and 

 produces a novel double effect, something like the cut of a whip. 



M. Guyot cTArlincourt. 



1706* Belay for Rapid Transmission. 



M. Guyot d'Arlincourt. 



Application of this relay for the transmission into the rapid apparatus. 

 In this same apparatus two other relays called whipcuts discharge the line 

 with each emission of the current. 



1707. Autographic Apparatus. M. Guyot d'Arlincourt. 



Employment of the circular vibration of the branches of a diapason for 

 regulating the working of the apparatus. New correcting system for ascer- 

 taining at once the isochronous action of two apparatuses that are not 

 regulated perfectly one upon the other. 



1708. Dial Printing Telegraph. M. Guyot d 'Arlincourt. 



Printing apparatus with electro-magnet of two planes and two effects ; one 

 of the planes at the open ends of the electro -magnet governs the recipient, the 

 other at the heel produces the impression of the letter. When the. positive 

 and negative currents are thrown alternately and without interruption, the two 

 planes act together, and the local circuit of impression is open. On the inter- 

 ruption of any current, the plane at the heel acts alone, the two planes are no 

 longer united, and the printing takes place. 



1709. Morse Sounder. Dumoulin Froment. 



1709a. Morse's " Sender and Receiver." 



Dumoulin Froment, Paris. 



1709b. Detector of Disorder in Pneumatic Telegraph 

 Tubes. M. Bontemps, Telegraph Inspector, Paris. 



a. With bell. 



b. With differential manometer. 



