Encouraged by this confirmation of his theories, Keely pursued his researches with renewed vigour. At this time he wrote, "I am straining every nerve to accomplish certain matters in a given time, working from twelve to fourteen hours daily. Although in my illness I have had some peaceful hours in thinking over the fascinating points associated with the researches to which I am devoting my life, I have also had some very stormy ones in reviewing the many unjust insinuations and denouncements that have been heaped upon me by the ignorant and the base-hearted. My one desire has been the acquisition of knowledge; and, no matter how great the impediment thrown in my path, I will work without ceasing to attain my end. After struggling for over seventeen years, allowing scientists to examine my machinery in the most thorough manner, and to make the most sensitive tests, denunciations have multiplied against me. One charge is that I use sodium in my mercury, in the vacuum test. I have thought that I would never again make any effort to prove that I am honest but I am working in a new lead, and for the satisfaction of the few friends that I have I propose to show my introductory evolutions, in proof of the negatization of an etheric substance to produce vacuum. The mercury may be delivered to me by an expert: I will operate from an open mercury bath: using the most perfect mercury gauge obtainable, attached to the same sphere that the column is operated from. Professor Rogers, the highest authority we have, saw the operation of inducing these etheric vacuum and pronounced the result wonderful. He said that the scientific world would go down on its knees, if I produced only one pound of vacuum under the conditions named. I showed from one to fourteen lbs. during the evolutions. . . . As soon as I have been able to combine all the positive and negative forces of etheric vibration in the triple vibratory sphere-engine that I am now at work upon in short, as soon as I have completed a perfect, patentable machine, then my labours will cease on the Motor line; and after my patents are taken out I will devote the remainder of my life to Aerial Navigation, for I have the only true system to make it an entire success in the vibratory lift and the vibratory push-process." [The Nature of Keelys Problems]