On his return to America he plunged eagerly into writing, but the springs of utterance were soon sealed by the death of his wife. Following on the losses of his mother and two of his children this was the fourth and most crushing bereavement within a very few years. His recovery of working powers was aided by the distraction that came from an invitation to deliver the distinguished Lowell Lecture Series in Boston in the winter of 1854-1855. These were to be twelve in number, on poetry in general and English poetry in particular. The task appealed to him as combining the beauty and truth to which he inclined to turn after his years of conflict. He threw himself whole-heartedly into the preparation and delivery of the lectures and succeeded admirably with his hearers; but the greater result was an indirect one. While they were in progress Longfellow offered his resignation of the Smith Professorship "of the French and Spanish Languages and Literatures ... and of Belles Lettres in Harvard College," a post he had filled since 1836. Seven candidates of no mean ability presented themselves for the vacant position, but the appointment was offered to Lowell, who had not applied for it, in preference to them all. He spent another year abroad before undertaking the work in the autumn of 1856, and held the position actively until 1877 and as emeritus professor until his death in 1891. In this work he was a scholar and a critic rather than a teacher. He gave almost no elementary instruction in the languages, and his methods with his classes were casual to the neglect of the usual college traditions. What he did for his students was to share with them his own broad experience of life and letters and to show them how the study of foreign literatures was one with the study of history and philosophy. Lowell's course of life, however, could never be restricted to any single channel. If he had found in 1850 that reform could not take up the whole of him, he now discovered that scholarship was not all-absorbing. As early as 1853 the question of establishing a new Boston magazine had been in the air. When its chief promoter, Francis H. Underwood,[20] had made certain of its start, Lowell was secured as first editor and carried it through the most critical period, until in 1861 it passed into the publishing hands of Ticknor and Fields and under the editorship of the junior member of that firm, James T. Fields. In the editorial office, as at Cambridge, Lowell was relieved from the heaviest humdrum labor (especially of correspondence) and was enabled to give his best energies to creative planning, yet it is interesting to see how effective were some of the detail criticisms accepted by poets like Emerson and Whittier and how vigilant he was in his reading of manuscripts and proof sheets. Throughout it all he kept up a spring-flow of boyish jollity, no different in spirit from that in his letters of college days.