In the same year Rochlitz, editor of the Leipsic _Music Journal_, offered him the text of the oratorio, "The Last Judgment," and he set to work on it at once. The oratorio was produced in the Lutheran church of Cassel, on Good Friday, Mar. 25, 1826, and made a deep impression. In 1827, he produced another opera, "Pietro von Albano," which in spite of Meyerbeer's enthusiastic praise, had little success. In 1831, he finished his "Violin School," a book of instruction which is still held in esteem though not regarded as the best. In 1832, political disturbances, in which Spohr played the radical and offended the Elector, interrupted the opera performances at Cassel for a long time, and the artist devoted his time to oratorio and instrumental composition. In 1832 he wrote his most noted symphony, "The Consecration of Tones," and in 1834 he was at work on his "Calvary," which was produced at Cassel on Good Friday, 1835. He went to England a second time in 1839, to conduct "Calvary" at the Norwich Festival. The success of the work was so great that he was commissioned to write "The Fall of Babylon" (the book by Edward Taylor) for the Norwich Festival of 1842. In 1840 he conducted a festival at Aix-la-Chapelle, and in 1842 he produced Wagner's "Der Fliegende Holländer" at Cassel. He had heard much in its praise from Dresden, and having read the work was at once pleased with it. In writing to a friend he said: "It interests me, nevertheless, in the highest degree, for it is written apparently with true inspiration--and unlike so much of the modern opera music, does not display in every bar the striving after effect, or effort to please. There is a great deal of the fanciful there-in; a noble conception throughout; it is well-written for the singer; enormously difficult, it is true, and somewhat overcharged in the instrumentation, but full of new effects, and will assuredly, when it once comes to be performed in the greater space of the theatre, be thoroughly clear, and intelligible.... I think I am so far correct in my judgment, when I consider Wagner as the most gifted of all our dramatic composers of the present time." This opinion of Spohr's is creditable to his judgment as a musician and his generosity as a man. He worked hard and gave a performance which pleased the public. He wrote to Wagner of the success of his work and received from the young composer one of his characteristic letters of gratitude.