The Collaborative International Dictionary
Dictograph \Dic"to*graph\ (d[i^]k"t[-o]*gr[.a]f), n. [L. dictum a thing said + E. -graph.] A telephonic instrument for office or other similar use, having a sound-magnifying device enabling the ordinary mouthpiece to be dispensed with. Much use has been made of it for overhearing, or for recording, conversations for the purpose of obtaining evidence for use in litigation.
Note: The makers of this instrument spell it dictograph.
Douglas Harper's Etymology Dictionary
patented 1907 in U.S. by K.M. Turner and W. Donnan, from dictation + -graph "instrument for recording; something written."
Usage examples of "dictograph".
Each time, he had heard only the dictograph cylinder in Doc Savage's office requesting him to leave a message.
Voice sound came from the ear phones as the dictograph began operation.
I suggested after we had nosed about for a few minutes, finding nothing, "that this is pre-eminently a case in which to use the dictograph as you did in that Black Hand case.
There were some anxious moments until at last they had satisfied themselves that no one was listening and that no dictograph or other mechanical eavesdropper, such as they had heard of, was concealed in the furniture or back of it.
I had already guessed that it was a dictograph, though I could not tell how it was used or who used it.
It is certain there is neither a dictograph installed here nor any means at Nogam's disposal for connecting with a dictograph installation.
So absolute was the submergence of that ardent adventurer who, overnight, had lain awake for hours, a dictograph receiver glued to his ear, eavesdropping upon the traffic of those malevolent intelligences assembled in Prince Victor's study, and alternately chuckling and cursing beneath his breath, aflame with indignation and chilled by inklings of atrocities unspeakable abrew!
This is my 'electric ear'--in other words the dictograph, used, I am told, by the Secret Service of the United States.
That meant Olive was wise to the Diane business, and he was shrewd enough to figure there might be a dictograph running into Pemberton's office.
Then be proceeded to wind up a length of fine wire attached to the dictograph, wire as fine as hair, and hence practically unnoticeable.