In 1872 the Bells moved to Canada, and young Alexander Bell became widely known in Boston as an authority in the teaching of the deaf and dumb. He first carried to great perfection in this country the art of enabling the deaf and dumb to enunciate intelligible words and sounds that they themselves have never heard. Most of his art he acquired from his father, one of the most expert of teachers in this field. The elder Bell is still active in his work, constantly devising new methods and experiments. He lives in Washington with his son and is frequently heard in lectures in New York and Boston. In 1873 Alexander Bell began to study the transmission of musical tones by telegraph. It was in the line of his work with deaf and dumb people to make sound vibrations visible to the eye. With the phonautograph he could obtain tracings of such vibrations upon blackened paper by means of a pencil or stylus attached to a vibrating cord or membrane. He also succeeded in obtaining tracings upon smoked glass of the vibrations of the air produced by vowel sounds. He began experimenting with an apparatus resembling the human ear, and upon the suggestion of Dr. Clarence J. Blake, the Boston aurist, he tried his work upon a prepared specimen of the ear itself. Observation upon the vibrations of the various bones within the ear led him to conceive the idea of vibrating a piece of iron in front of an electro-magnet. Mr. Bell was at this time an instructor in phonetics, or the art of visible speech, in Monroe's School of Oratory in Boston. One of his old pupils describes him then as a swarthy, foreign-looking personage, more Italian than English in appearance, with jet-black hair and dark skin. His manner was earnest and full of conviction. He was an enthusiast in his work, and only emerged from his habitual diffidence when called upon to talk upon his studies and views. He was miserably poor and almost without friends. When he was attacked with muscular rheumatism, in 1873, his hospital expenses were paid by his employer, and his only visitors were some of the pupils at the school. Until the close of 1874, Bell's experiments seemed to promise nothing of practical value. But in 1875 he began to transmit vibrations between two armatures, one at each end of a wire. He was much interested at the time in multiple telegraphy and fancied that something might come of some such arrangement of many magnetic armatures responding to the vibrations set up in one.