whoever you choose, and I will convince you and 

 them that my perpetual motor drives the grindstone; 

 you may cast the belt, or do whatever you like." 



My father, who seemed hurt by the language that 

 had been used, believing it was due to Redheffer to 

 give him the chance, reluctantly agreed, and a time 

 was fixed. My father took with him my uncle, 

 Rubens Peale, Isaiah Lukens, and I think, either 

 William Mason or Rufus Tyler — most probably the 

 latter, as he was the most frequent visitor at our house, 

 and the open-front carriage my father drove only 

 carried four persons. Lukens was the town clock- 

 maker and general machinist; no man of that period 

 better known, or held in higher estimation. Both 

 Mason and Tyler were accomplished machinists, 

 makers of the highest order of philosophical instru- 

 ments, fine-class foot lathes, slide rests and models. 

 I have often heard Lukens relate the incidents of this 

 visit in a most humorous way, made more so by his 

 impediment in speech, when telling anything exciting. 



They found the grindstone removed from its position 

 near the partition, the belt cast, the stone standing, 

 and the motor running; the only change my father 

 observed was in the position of the bevel wheels — the 

 crown wheel that had been under that of the hori- 

 zontal shaft was now on top. This change Redheffer 

 explained as having been made to admit of being 

 thrown out of gear, on raising the shaft out of its 

 step-box, that the length of the rounds of the lantern 

 pinion admitted of his doing so; he thought that would 

 convince Coleman Sellers that the power that ran his 

 motor did not come by the way of the grindstone, but 

 was due entirely to the weights on the carriages. The 

 machine was stopped, and propped to prevent starting; 

 the shaft was raised sufficiently out of its step-box, 

 as Lukens used to describe it, to admit of passing a 

 knife blade under; that was all the rounds of the 

 lantern pinion would allow, but, as Lukens said, not 

 sufficient to let him put his finger under, to feel if the 

 bottom of the shaft was not like the pipe of a watch 

 key, that, on being lowered, would connect with the 

 power, that, on signal, might start in the adjoining 

 room. 



Then he, without giving any reason for so doing, 

 was about asking of Redheffer the privilege of taking 

 the upright shaft down with its lantern pinion, and 

 allowing the machine to run without that appendage, 

 when he was interrupted by my father saying to 

 Redheffer, "Your machine is beautifully finished in 

 all its parts; why was it not carried out in this?" 



putting his cane on a plank or timber rather roughly 

 hewed, showing the marks of the broadaxe. 



To this Redheffer's reply was, "I was in a hurry 

 making the changes, and as it is entirely outside, and 

 not connected with or essential to the machine, I 

 let it go." 



"Yes, yes, I see it is not, but it does not seem to be 

 securely fastened, and could be easily removed 

 without the least injury to the machine; if you will 

 sell it to me, and let me take it up now, I will give 

 you one hundred dollars for it, and you can replace 

 it for less than one dollar." 



It was here, in telling the story, that Lukens, in 

 his inimitable way, mimicked Redheffer's rage, when 

 indignantly rejecting an offer that he took as an 

 insult. The telling was so amusing that we never 

 tired of hearing it repeated. Father had rightly 

 surmised that the plank in question covered the 

 entire secret. 



Rubens Peale was at that time manager of the 

 Philadelphia Museum, belonging to his father; he 

 conceived the idea that the furor raised by Redheffer 

 might be turned to advantage, if a working model 

 of the perpetual motion could be so constructed that 

 the power moving it could not be discovered, it 

 would prove attractive. This Isaiah Lukens under- 

 took to do, and made rather a rude working model. 

 This, I think, is still in existence in the collection of 

 the Franklin Institute of Philadelphia." 3 This did 

 not carry out the perfect deception required, and 

 in its exhibition needed the constant attention of 

 someone to manipulate it, to stop on the removal 

 of the weights, and to start on their being replaced. 

 The lower journal or step of the upright rested on 

 a plate glass that could be removed, and the upright 

 with its platform wheel raised or lowered, but would 

 hold this shaft perpendicular. Above this glass step 

 there was a light bridge, but heavy enough to have 

 the power from clock work in the base by light, 

 delicate gearing, to carry the power to the upright 

 through it; this was a step in the right direction, but 

 it did not meet the case. But to make a working 

 model that would start on placing the weights on 

 the inclined beds of the railway carriages, and stop 



113 I saw the model, in i960, in storage at the Franklin 

 Institute. Another model was made by Lukens in 1822 for 

 the Peale Museum in Baltimore (letter from Rubens to Franklin 

 Peale dated June 11, 1822, in American Philosophical Society 

 Library, pointed out by Wilbur H. Hunter, Jr., "Tribulations 

 of a Museum Director in the 1820's," Maryland Historical 

 Magazine, September 1954, vol. 49, pp. 214-222). 



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