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." It will be seen that, at this stage, Keely had no idea of giving up the engine; and was still as confident of ultimate success as in the beginning. There is no doubt that, had not the time arrived when the directing power of Providence led him away in quite another direction from the line that he was then working upon, his system for Aerial Navigation would have been lost to this century. "The heart of man deviseth his way, but the Lord directs his steps." About this time Keely met with an accident. Under date March 22nd, he wrote, "It has been impossible for me to write, my right hand and arm were so severely strained, but I have not been idle. I have had time for reflection, and I have been setting up a key to explain vibratory rotation. I have also a plan for a device to be attached to the Liberator as an indicator to show when the neutral centre is free from its intensification while operating. In this way the dangerous influences will be avoided which present themselves on the extension of the vibratory waves that operate the gun. All the introductory details of the present engine are as perfect as is possible for the first lead. It is in the form of a sphere, about thirty inches in diameter and weighs 800 lbs. Yesterday saw the pure, positive action of my new Liberator. Mr. Collier and his brother George were present, and witnessed thirty expulsions, made by myself; after which I had them produce the vapour, by imitating my manipulations; which they were unable to do with the old generator. They were very much delighted. To say that the last three weeks have been trying ones, is using very mild language to express what I have suffered from accidents, disappointments, etc., etc. I have been frozen in at my workshop; and all things seemed to go wrong; but my present successes are as an anchor, which I thank God for, who, in His bountiful goodness, has carried me into a port of safety over tempestuous seas." Again, under various dates, Keely wrote:--"Unbounded success has crowned my new departure. I am now preparing new features that are necessary as adjuncts to denote the true condition, as regards safety in my different vibratory operations." "Without the aid sent me from on high there would have been nothing left of the discovery mechanically; nor