Mr. Clarke in reply to Mr. Saxton. 457 



for quantity being double the diameter of the intensity cylin- 

 ders) ; different as respects the relative thickness of the wires 

 (the intensity wire being ^'^ of an inch in diameter and 1500 

 yards long, the quantity wire being -^-^ inch in diameter and 

 40 yards long) ; different also in my armatures being separate, 

 for were they to be in one piece, to develop the full effects of 

 both quantity and intensity the poles of the magnetic battery 

 should be separated more than three times the distance they 

 now are by my having the armatures unconnected. And yet 

 this is what Mr. Saxton would call " a slight variation in the 

 situation of the parts" ! 



" I now come to speak of Mr. Saxton's statement respecting 

 the quantity and thickness of the wire he uses ; for I confess 

 that I for one, on referring to his figures ^ and 4, cannot ima- 

 gine that he has ever constructed an instrument of the kind 

 he describes. It must be evident that the quantity of wire re- 

 quired for C D, would be so disproporticmate to that neces- 

 sary for A B, as to render necessary a greater space between the 

 cylinders C D (containing the quantity of thick wire), and the 

 cylinders A B, having a smaller quantity of thin wire. 



" Again, Mr. Saxton speaks of insulation^ saying that the 

 front end of the spindle is for that purpose, being made of 

 ivory or hard wood. Insulation of what ? I use nothing of the 

 kind ; insulation being quite unnecessary. Will Mr. Saxton 

 still maintain that my machine does not differ in principle also 

 on this point ? Next we come to his description of the ar- 

 rangement for giving the spark. According to his description, 

 if the blade F leaves the surface of the mercury at the* moment 

 when the cylinder C D is vertical, then A B being on the mag- 

 nets, and the current in C D having been for some time neu- 

 tralized, the proper point would be so far different from what 

 he states, as, instead of being vertical, to form an angle of 

 nearly 45°. ' For obtaining the shock,' says Mr. Saxton, 

 ' the points should be removed,' &c. I answer, Let any 'per- 

 son try to obtain the shock with the points removed. 



'* He omits to state to whom he is indebted for the sugges- 

 tion of removing one of the points. But I shall take the liberty 

 of doing so, and he will remember that the individual alluded 

 to was Mr. Ellicott, assistant to Charles Payne, Esq., late the 

 deservedly respected Superintendent of the Adelaide Gallery, 

 who is perfectly ready and willing to prove the correctness of 

 this statement. We now come to what may be called the 

 historical portion of Mr. Saxton's paper, and here I would 

 remark, that if I had written a history of magnetic machines, 

 instead of merely describing my own, and had omitted to 

 mention any one in particular, I then might have fairly been 



Third Series, Vol. 10. No. 63. June 1837. 3 N 



