190 AUTOBIOGRAPHY OF JOHN FRITZ
strong in order to resist the force of the blow, without breaking. The latter was a most difficult problem to solve.
The EngUsh navy adopted the compound system, with soft back of wrought iron or low-carbon steel, and high- carbon steel on the front or face of the plate. There were three ways of combining the metals, that seemed to be the favorites; the results were all the same, but cUfferent plans were devised to accompUsh the same result. One was to form a mould of the proper material to stand the heat of the molten steel, and of the proper size to make the finished plate. This was placed on edge in the floor; then a wrought- iron or a soft-steel plate of the proper size to make the plate, but less in thickness than the pattern, was put in a heating furnace and heated to a welding heat, and placed in the mould, close to one side ;j this left a space which was filled with hard steel to make the face of the plate. This all had to be done in the quickest time possible, in order to get the adhesion of the two metals on which the value of the plate largely depended. When it cooled to the proper tempera¬ ture, it was taken to the roUs or the press, and was finished to the proper thickness, then to the machine tools, and was finished to the proper size for the vessel.
A large amount of money was expended on these experi¬ ments, which were wrong in both theory and practice. In the first place, the plates were not welded perfectly, which was essential in order to make a good armor plate; then the soft back was a mistake, as it was not at all possible to get the required strength with soft metal to support the back against the shock; and great strength in the back of an ar¬ mor plate is an aU-important element, and one that is most difficult to get. My first thoughts on the subject soon led me to think that a soUd steel plate was the best, and that good steel was the best material. When I first wanted the company to bmld a forge plant and put in a hammer, I had