Both Gray and Torrey were elected to the American Academy of Arts and Sciences in December 1841. Gray never returned to teach a course at Michigan. In 1833 Dr.Joshua Fisher, a resident of Beverly, Massachusetts, and a Harvard University alumnus, bequeathed $20,000 to Harvard to endow a chair in natural history. The university allowed the proceeds to accumulate until it could fund a full year's salary for a professor. Because of this and a few problems in finding a suitable professor, this chair was not filled until it was formally offered to Gray on March 26, 1842. The offer was $1,000/year salary, teaching duties limited to only botany, and being superintendent of Harvard's botanic garden. While the salary was low, the teaching limitation, rare for the time, allowed him plenty of time to do research and work in the botanic garden. After an exchange of letters, Gray accepted this appointment as Fisher Professor of Natural History at Harvard. The formal appointment was made April 30, 1842. Gray arrived at Harvard on July 22, 1842, and began his duties in September. He did not have to teach in the fall of 1842, but began in spring 1843, the first classes he had taught in nine years. Early in his years at Harvard, Gray had to borrow money from his father. Soon he was able to repay his father and help his family by supplementing his income giving lectures outside of Harvard, including at the Lowell Institute. Gray was considered a weak lecturer, but because of his expert knowledge, he was highly regarded by his peers. His skills were better suited to teaching advanced rather than introductory classes. He also gained renown for his textbooks and high quality illustrations. Gray moved into what became known as the Asa Gray House in the Botanic Garden in the summer of 1844. It had been built in 1810 for William Dandridge Peck and later occupied by Thomas Nuttall. As the demands of teaching, collecting, selling specimens, taking care of the herbarium, and writing books increased and he himself was not a good illustrator, Gray found it necessary to hire a botanical illustratorIsaac Sprague, who illustrated much of Gray's works for decades to come.