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. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . United States Patent Office^ THOMAS A. EDISON, OF NEWARK, NEW JERSEY, ASSIGNOR TO HIMSELFAND MARSHALL LEFFERTS, OF NEW YORK CITY. IMPROVEMENT IN RELAY-MAGNETS FOR TELEGRAPH-INSTRUMENTS. Specification forming part of Letters Patent No. 114,657, dated May 9, 1871. To all whom it may concern : Be it known that I, Thomas A. Edison, ofNewark, in the county of Essex and State ofNew Jersey, have invented an Improvementin Electro-Magnets; and the following is de-clared to be a correct description thereof. The object of this
. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . United States Patent Office^ THOMAS A. EDISON, OF NEWARK, NEW JERSEY, ASSIGNOR TO HIMSELFAND MARSHALL LEFFERTS, OF NEW YORK CITY. IMPROVEMENT IN RELAY-MAGNETS FOR TELEGRAPH-INSTRUMENTS. Specification forming part of Letters Patent No. 114,657, dated May 9, 1871. To all whom it may concern : Be it known that I, Thomas A. Edison, ofNewark, in the county of Essex and State ofNew Jersey, have invented an Improvementin Electro-Magnets; and the following is de-clared to be a correct description thereof. The object of this invention is to produce anelectro-magnet that can be operated with greatrapidity and accuracy, and capable of being-used as a relay or repeater for a chemical tele-graph operated by punched paper and a stilusor brush circuit-closer, or for a time-repeaterin astronomical or other observatories, or fora relay or repeater to a Morse telegraph-instru-ment, or wherever great rapidity or accuracyof movement is required. I make use of a soft-iron core to a short sin-gle-spool ele
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