Following this successful result, I built a laboratory at a dynamite plant near Lake Hopatcong for conducting the experiments on a larger scale. My assistant at the motorite laboratory was one of that American country type, absolutely honest, perfectly fearless, painstaking and diligent, of such timber as the great men of the earth are made. He was altogether a most lovable fellow. He had all his life worked with explosives, and was a veteran in the manufacture and use of nitroglycerin and dynamite. But, when doing pioneer work with explosives, there is always an unavoidable element of risk, even when the greatest care is taken. We at first had the hydraulic press, in which we built up the sticks of motorite, located in the laboratory room itself; but I suggested to my assistant one day that it had better be placed outside, and a heavy brick wall built between us and the press, as a barricade in case of a possible accident. "For," I said, "suppose you should by oversight neglect to put in the leather packing between the piston and the motorite, we might have an explosion." He said that he could hardly forget that precaution. Nevertheless, the press was placed outside, and the barricade built. The very first time that we used the press thereafter he did forget the packing, with the result that the press exploded. Although we were behind the barricade, still the concussion brought us to our knees. Had the explosion occurred while the press was being operated in the main laboratory, we should both have certainly been very seriously injured, if not killed. It was a matter of several months before the full-sized torpedo apparatus with which we were to experiment was completed and erected, and the necessary quantity of motorite made. On the day before the regular test was to be conducted, I was called to Morristown, as expert on a case in court, and I left orders with my assistant to make up an additional small quantity of sealing compound, used for sealing the discs of motorite together in building up the bars. This sealing material was made of a mixture of nitroglycerin, guncotton, camphor and acetate of amyl. As I did not receive the telegram to go to Morristown until after I left home that morning, my wife expected that I would be working at the laboratory that day, but knew that I might possibly have a call to Morristown. On my way home that evening, I was informed by a neighbor that there had been an explosion in my laboratory, that my assistant had been killed, and that the place had been burned down. I hastened to the spot and found my wife there waiting for me. All that was left of my assistant lay in an adjacent building covered with a piece of sacking. That was one of the saddest moments of my whole life. It is impossible to know what little slip or misjudgment may have produced the explosion. A little inadvertence in the handling of a bottle of nitroglycerin may have been the cause.