Extract the answer to the question from the following context. Question: Who's father help him set up his private practice by contacting Gardiner Greene Hubbard? Context: Unsure of his future, he first contemplated returning to London to complete his studies, but decided to return to Boston as a teacher. His father helped him set up his private practice by contacting Gardiner Greene Hubbard, the president of the Clarke School for the Deaf for a recommendation. Teaching his father's system, in October 1872, Alexander Bell opened his "School of Vocal Physiology and Mechanics of Speech" in Boston, which attracted a large number of deaf pupils, with his first class numbering 30 students. While he was working as a private tutor, one of his most famous pupils was Helen Keller, who came to him as a young child unable to see, hear, or speak. She was later to say that Bell dedicated his life to the penetration of that "inhuman silence which separates and estranges." In 1893, Keller performed the sod-breaking ceremony for the construction of the new Bell's new Volta Bureau, dedicated to "the increase and diffusion of knowledge relating to the deaf".
The answer to this question is:
Alexander Bell