In 1820, his twelfth year, he set about composing regularly. With that year begins the series of forty-four volumes in which he methodically preserved autograph copies of a great part of his works down to the time of his death, with date and place carefully noted. These are now in the Imperial Library at Berlin. Another proof of his methodical self-discipline is found in the fact that for many years he made it an invariable rule to compose _something every day_. His productive activity during the six early years from 1820 to 1826 was incessant, many-sided and prolific. In 1820, among other compositions named by Grove, are a Trio for piano and strings; a Sonata for pianoforte and violin; another for pianoforte solo; four organ pieces; a Cantata, bearing the earliest date of all (Jan. 13); a Lustspiel for voices and pianoforte, in three scenes, beginning: "Ich Felix Mendelssohn," etc. In 1821, five Symphonies for strings, songs, one-act operas. This was the year when Zelter first took him to Goethe at Weimar. The next two years were no less productive. In the summer of 1822 the whole family made a leisurely tour in Switzerland, visiting on the way Spohr at Cassel, on the return Schelble, conductor of the famous Cäcilien-Verein at Frankfort, and Goethe again at Weimar. Near Geneva he wrote the first (Op. I) of three Quartets for pianoforte and strings. In the two years six more quartet Symphonies, making twelve in all, which do not figure in the catalogue, although they were not mere exercises. Then, too, an opera, "The Uncle from Boston," in three acts. He was then nearly fifteen, growing fast, his features and expression altering and maturing, and his hair cut short. It is pleasant to read of the Sunday morning music in his grandmother's large dining-room, with a small orchestra, Felix conducting, Fanny or himself at the piano, Rebecka singing, and the young brother Paul playing the 'cello. Some composition of his own had place in every programme. Noted musicians passing through Berlin were often present. For critic there was his own father, besides the wise old Zelter. Every evening, also, more or less, the house was enlivened by music, theatrical impromptus, and "constant flux and reflux of young, clever, distinguished people, who made the suppers gay and noisy, and among whom Felix was the favorite." Among the intimates were Moscheles and Spohr. [Illustration: MENDELSSOHN'S FATHER. Abraham Mendelssohn--from a pencil drawing made by his son-in-law William Hensel.]