What does the word telegraphy mean?

Usage examples for telegraphy

  1. At a mile above earth, however, this difficulty is not presented, and it may be that a superior kind of wireless telegraphy will be introduced some day by the use of talking balloons. – Careers of Danger and Daring by Cleveland Moffett
  2. From far away, carried by the telegraphy of the earth- and there are few conductors that are better- was the steady pound, pound, pound of shock after shock as it traveled along the hanging wall. – The Cross-Cut by Courtney Ryley Cooper