I am enjoying Edith Wharton
The Age of Innocence and came across this reference to an early wiring instrument in chapter XXIII
Newland Archer, a wealthy New Yorker has married a very beautiful girl from a grand NY family. They are spending part of the summer near Newport, but Archer finds himself attracted to a married woman he knew before he was married. He escapes to Boston and meets Madame Olenska (she is still married, but separated from a European nobleman).
Needing to write a note while they are in a park, Archer lends Madame Olenska a writing instrument:
"You can write here." He drew out a note-case and one of the new stylographic pens. "I've even got a envelope—you see how everything is predestined! There—steady the thing on your knee, and I'll get the pen going in a second. They have to be humoured; wait—" He banged the hand that held the pen against the back of the bench. "It's like jerking down the mercury in a thermometer: just a trick. Now try—"
She laughed, and bending over the sheet of paper which he had laid on his note-case, began to write. Archer walked away a few steps, staring with radiant unseeing eyes at the passers-by, who, in their turn, paused to stare at the unwonted sight of a fashionably-dressed lady writing a note on her knee on a bench in the Common.
Hmm. There'll be trouble...