In Coblentz, where he was much occupied with duty, he could only give occasional hours to his private studies. It was not until 1818, after his appointment as Director of the General Academy of War at Berlin, that he had the leisure to expand his work, and enrich it from the history of modern wars. This leisure also reconciled him to his new avocation, which, in other respects, was not satisfactory to him, as, according to the existing organisation of the Academy, the scientific part of the course is not under the Director, but conducted by a Board of Studies. Free as he was from all petty vanity, from every feeling of restless, egotistical ambition, still he felt a desire to be really useful, and not to leave inactive the abilities with which God had endowed him. In active life he was not in a position in which this longing could be satisfied, and he had little hope of attaining to any such position: his whole energies were therefore directed upon the domain of science, and the benefit which he hoped to lay the foundation of by his work was the object of his life. That, notwithstanding this, the resolution not to let the work appear until after his death became more confirmed is the best proof that no vain, paltry longing for praise and distinction, no particle of egotistical views, was mixed up with this noble aspiration for great and lasting usefulness. Thus he worked diligently on, until, in the spring of 1830, he was appointed to the artillery, and his energies were called into activity in such a different sphere, and to such a high degree, that he was obliged, for the moment at least, to give up all literary work. He then put his papers in order, sealed up the separate packets, labelled them, and took sorrowful leave of this employment which he loved so much. He was sent to Breslau in August of the same year, as Chief of the Second Artillery District, but in December recalled to Berlin, and appointed Chief of the Staff to Field-Marshal Count Gneisenau (for the term of his command). In March 1831, he accompanied his revered Commander to Posen. When he returned from there to Breslau in November after the melancholy event which had taken place, he hoped to resume his work and perhaps complete it in the course of the winter. The Almighty has willed it should be otherwise. On the 7th November he returned to Breslau; on the 16th he was no more; and the packets sealed by himself were not opened until after his death.