The roar of the escaping gas and steam was so great that it was impossible to hear one shout at the top of his voice. The loudest shout was less than a whisper. The roar could be heard with great distinctness more than two miles away. A good idea can be had of the violence with which the steam and gases escaped, from the fact that a door, which accidentally swung shut during one of the runs in front of the nozzle, although seven feet distant, was blown from its hinges, broken in two, and the fragments hurled twenty feet away. The noise was so confounding, that it was some time before my assistants and myself could keep our senses about us and note and record the pressures on the various gauges during a run, although the apparatus was separated from us by a barricade so strong and heavy that there was no possibility of our being injured, even should there be an explosion.
One day, just as we were about to make a run, the superintendent of a nearby explosives works called upon us, and I asked him if he would like to see the run, and he said he would.
I then asked him to note particularly and to record the pressure on a certain gauge. The run lasted about five minutes and, on turning to him for his notes, he himself was surprised that he had been so confounded by the noise that he had not thought of looking at the gauge at all.
On the day when the final test took place, the firm of torpedo-builders that was interested with me in the apparatus sent several representatives, including their chief engineer, vice-president and other officers of the company, to witness the test. Everything being in readiness, and each member of the committee being convinced that there was no possible danger in remaining in proximity to the apparatus and back of the barricade, while it was being tested, I gave each of the committee explicit instructions to watch the various gauges and to note the pressures, while the chief engineer and myself were to watch the nozzle gauge, and to observe the character and force of the steam and gases escaping from the nozzle.
I told the several members of the committee it was indispensable that they should carefully watch the pressure gauges during the entire run. As it was a condition of the test that I should get up steam within ten seconds, the chief engineer stood ready with his stop-watch when the electric button was pressed to ignite the motorite.