So engrossed have been governments, inventors, capitalists, and the public in general, in the development of the submarine vessel for military purposes, and in the perfection and augmentation of its capabilities as a destructive agent, that they have never considered or realized that submarines and submarine appliances possess a wide range of utility as productive instruments in commercial and industrial operations. This concentration of energy upon the construction of military submarines I believe to have been a very desirable thing, and the success which has been attained therein, I am convinced, augurs propitiously for the future well-being of the world. It is time now, however, to take up the development of the submarine for industrial purposes. The world stands in need, to-day, of services which the submarine is uniquely able to render. While great publicity has been given to the art of submarine navigation as applied to warfare, little or nothing has been published, outside of scientific journals, as to the productive capacity of submarine devices. It seems desirable, therefore, to devote a few pages to consideration of the submarine in this other field of action. I myself have devoted the greater part of my own efforts to the construction of military submarines. But, in the early years of my work as a constructor of under-water vessels I was greatly attracted to this branch of submarine work, and from that time to the present I have spent a great deal of time and money in developing submarine appliances to be turned to peaceful uses. It is my aim to go into this work quite extensively when peace is restored to the world. At present, however, problems of national defence are occupying the attention of every naval architect. I shall present in this chapter a few suggestions as to the uses to which submarine appliances may be turned as productive agents, and I shall speak briefly and simply as to the mode of operation of such devices. Many of the things of which I will write have actually been accomplished in vessels constructed by me. Others of which I write are now under process of construction. Still others are as yet visionary, but not at all impossible. Nothing of which I write do I believe to be impractical or improbable. The submarine can do many things in a new, more economical, and more productive way. One important use to which the commercial submarine may be turned is that of navigating under ice fields, between ports which are bound with ice fields during great parts of the year, and also for purposes of exploration and of scientific study.