. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . 7 of Essex and State ofNew Jersey, have invented an Improvementin Recording-Points for Chemical Telegraphs,of which the following is a specification: I have found that if the decomposing andrecording point of a chemical telegraph bemade of metallic ruthinium, and connectedto the positive pole of the battery, a colo-ration is made upon nearly dry paper, whichhad been moistened with various chemicalsolutions, preferably ferro-cyanide of potas-sium and chloride of sodium. The reaction 105. is of extreme delicacy, the m

---

. Collection of United States patents granted to Thomas A. Edison, 1869-1884 . 7 of Essex and State ofNew Jersey, have invented an Improvementin Recording-Points for Chemical Telegraphs,of which the following is a specification: I have found that if the decomposing andrecording point of a chemical telegraph bemade of metallic ruthinium, and connectedto the positive pole of the battery, a colo-ration is made upon nearly dry paper, whichhad been moistened with various chemicalsolutions, preferably ferro-cyanide of potas-sium and chloride of sodium. The reaction 105. is of extreme delicacy, the marks being dueprobably to the finely-divided oxide of ruthini-um formed by the electrolytic claim— Arecording-point formed of metallic ruthini-um in a chemical telegraph, substantially as setforth. Signed by me this 18th day of January, A. THOS. A. EDISON. Witnesses: Geo. T. Pinckney,Chas. H. Smith. I T. A. E 0 { S0 N .Transmitter and Receiver for Automatic Telegraphs. No. 168,242. Patented Sept. 28, to °Q .© <T qc,

---

Size: 2064px × 1211px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: ., boo, bookcentury1800, booksubjectinventions, booksubjecttelephone