He had not been forgetful of "Visible Speech" all this while, but had been making experiments with two remarkable machines--the phonautograph and the manometric capsule, by means of which the vibrations of sound were made plainly visible.

If these could be im-proved, he thought, then the deaf might be taught to speak by SIGHT--by learning an alphabet of vibrations.

He mentioned these experiments to a Boston friend, Dr.Clarence J.Blake, and he, being a surgeon and an aurist, naturally said, "Why don't you use a REAL EAR ?" Such an idea never had, and probably never could have, occurred to Bell; but he accepted it with eagerness.

Dr.Blake cut an ear from a dead man's head, together with the ear-drum and the associated bones.

Bell took this fragment of a skull and arranged it so that a straw touched the ear-drum at one end and a piece of moving smoked glass at the other.
Thus, when Bell spoke loudly into the ear, the vibrations of the drum made tiny markings upon the glass.
It was one of the most extraordinary incidents in the whole history of the telephone.