He was wholly a man of enthusiasms, more devoted to ideas than to people; and less likely to master his own thoughts than to be mastered by them.

He had no shrewdness, in any commercial sense, and very little knowledge of the small practical details of ordinary living.
He was always intense, always absorbed.

When he applied his mind to a problem, it became at once an enthralling arena, in which there went whirling a chariot-race of ideas and inventive fancies.
He had been fascinated from boyhood by his father's system of "Visible Speech." He knew it so well that he once astonished a professor of Oriental languages by repeating correctly a sentence of Sanscrit that had been written in "Visible Speech" characters.

While he was living in London his most absorbing enthusiasm was the instruction of a class of deaf-mutes, who could be trained to talk, he believed, by means of the "Visible Speech" alphabet.

He was so deeply impressed by the progress made by these pupils, and by the pathos of their dumbness, that when he arrived in Canada he was in doubt as to which of these two tasks was the more important--the teaching of deaf-mutes or the invention of a musical telegraph.
At this point, and before Bell had begun to experiment with his telegraph, the scene of the story shifts from Canada to Massachusetts.
It appears that his father, while lecturing in Boston, had mentioned Graham's exploits with a class of deaf-mutes; and soon afterward the Boston Board of Education wrote to Graham, offering him five hundred dollars if he would come to Boston and introduce his system of teaching in a school for deaf-mutes that had been opened recently.