"I don't know why I write science fiction. The voices in my head told me to!"
- Charles Stross

The caption reads as follows:

(Every evening, before going to bed, Pater and Materfamilias set up an electric camera obscura over their bedroom mantel-piece, and gladden their eyes with the sight of their Children at the Antipodes, and converse gaily with them through the wire.)

Paterfamilias (in Willow Place): “Beatrice, come closer, I want to whisper.”

It has been pointed out that the dimensions of the screen in the drawing shown by du Maurier are almost identical to an aspect ratio of 2.76:1. The wide screen image depicted in this 1879 India ink drawing is equal to today's Ultra Panavison 70mm film format. Although large format film has been used since the late 1880's, this ratio was not seen until Ben Hur in 1959. For comparison purposes, the aspect ratio of 4K television is 1.9 to 1.

The telephonoscope also had some Zoom conferencing capabilities:

(Robida conference call)

"My wife is visiting her aunt in Buda-Pest, my eldest daughter studies at the dental institute in Melbourne, my youngest is a mining engineer in the Urals, my son breeds ostriches in Batavia, my nephew is at his plantations in Batavia, but that doesn't stop us from celebrating Christmas together through the telephonoscope.

In 1927, Garett Smith makes good use of the word in Treasures of Tatalus:

(Treasures of Tantalus by Garett Smith)

Fleckner’s magic rays swept this vast ocean from end to end, finally locating the vessel wrecked on a South Sea Island inhabited by lawless Bolshevic refugees from the rehabilitated Republic of Russia. At the moment, the outlaws were about to fall on the defenseless ship’s company and destroy them.

Flere Tom Priestley sprang into action. Fleckner had been experimenting with some new types of fire¬ arms for hunting purposes. There were several in a rack at the side of the laboratory—some loaded.

With these Priestley armed the company in the laboratory and placed them before the screen. He directed Fleckner to hurl our images between the refugees and the bandits and told every one to shoot and brandish weapons.

Well do I remember my intense amazement, when, after being told to look out of the window to the sidewalk some fifty stories below and note the silent figures moving about there, I suddenly saw a section of the sidewalk on the screen beside me as though the room were on the street level and the conversation of passers-by was heard as distinctly as if we were brushing elbows with them.

It was really no more marvelous than many other inventions of the last hundred years. The first tele¬ graph and the first telephone were as amazing in their day. The phonograph and the motion picture seemed like miracles. .When men learned to telephone without wires early in the Twentieth Century it seemed as though the climax had been reached. The telephonoscope which carried both voice and images and could range about at will was really only a short step farther. The wonder is that it was delayed so long.