The Whitehead torpedo was an invention of the highest order of brilliancy of conception; but, unlike many other inventions of this class, it has been a matter of the utmost difficulty to develop it. The possible usefulness suggested was so great that the principal European nations, especially the Germans and English, went about its development at once; but the practical difficulties encountered were so many and so great, and the opportunities of testing out its usefulness in actual warfare were so few, that it was not until after its successful and important use in the war between Russia and Japan in 1904-1905, that the torpedo was accepted as a major weapon. This invention is one of the most important contributions ever made to the self-protectivity of the Machine of Civilization; not only because of its immediate usefulness in war, but because its complexity necessitates such skill and knowledge in the operators, and its cost is so great, that only the most wealthy and highly civilized nations are able to use it successfully. As has been pointed out repeatedly in this book, one of the influences of invention on history has been to urge nations to a high degree of civilization, under pain of greater or less subjection to nations more highly civilized. In 1866 Wilde in England and Siemens in Germany invented dynamo electric machines, in which the magnetic field was made, not by permanent steel magnets, but by electro-magnets of soft iron that were energized by the current which the machine itself produced. This was an invention of the utmost practical value; but who was the actual inventor does not seem to be exactly known. Its main value is in its ability to produce a much more powerful current than could be produced when using permanent magnets; caused by the fact that electro-magnets can create a "magnetic field" much stronger than steel magnets can. In 1867 Tilghman invented his sulphite process for pulp making, and in 1868, Moncrief invented his famous disappearing gun-carriage. This was an invention requiring a high order of conception and constructiveness; it resulted in a considerable improvement in the art of sea-coast defense, and therefore in the self-protectiveness of the Machine, by keeping the guns safe behind fortifications except when actually being fired. Moncrief's carriage, although originally very good, has been improved upon from time to time; whenever the progress of the mechanic arts has made it possible, and some inventor has realized the fact.