Not only does our small-arms powder effect a great saving in the wear and tear of our shoulder-rifles, but also our pure nitro-cellulose cannon-powder effects a similar saving in the life of our big guns. Our big guns, using pure nitro-cellulose powder, last, with equal accuracy, more than twice as long as British guns, which use cordite. It will be seen from the foregoing considerations and figures that private genius and private enterprise alone have saved the government very many millions of dollars. Of course, it may be argued that, since guns and ammunition and all kinds of military implements and engines have been perfected, there is not now room for civilian inventors to be so useful to the government during the next twenty-five years as they have been in the past twenty-five. A similar attitude of the average mind would have existed had the same question been raised twenty-five years ago. When our Patent Office was first established, the Commissioner of Patents predicted that within fifty years everything possible of invention would have been invented and that then the Patent Office would have to be abolished for lack of business. The number of inventions received by the Patent Office, however, has rapidly increased, and is still rapidly increasing. More inventions are received now each year at the Patent Office than were received during the first fifty years of its existence. The reason for this is that every invention, either directly or indirectly, creates a demand for other inventions. The inventor is still working in virgin soil, and the room for invention is infinite. If the manufacture of war-materials were to be nationalized, not only would the government rob itself of the aid of large quasi-government manufactories, but also it would rob itself of the benefits of the inventive genius of the whole people. The value of that genius may be approximated by recalling what citizen inventions have done since the outbreak of the American Civil War.