456 Mr. Clarke in reply to Mr. Saxton. 



chinery is attached to the magnet: a glance at tlie figure in 

 Mr. Saxton's paper will at once prove the truth of this asser- 

 tion. Another disadvantage attending his instrument is, that 

 the magnetic batter}' cannot be readily detached so as to be 

 applied to other purposes. Then again comes the mercury 

 cup with all its attendant trouble and loss of time, owing to 

 the incessant scattering of the mercury, the necessary filtra- 

 tions owing to its oxidations, &c. 



" Let me now oppose to these evils the advantages which I 

 may fairly claim as being possessed by my machine. First, 

 the instrument can be worked without any possibility of vibra- 

 tion, and the magnetic battery can be withdrawn from the 

 instrument with the greatest facility. I have now also suc- 

 ceeded in dispensing with mercury, for a description of the 

 mode of doing which I beg leave to refer your readers to the 

 second number of Mr. Sturgeon's « Annals of Electricity, 

 Magnetism and Chemistry, and Guardian of Experimental 

 Science,' which also contains a description of my magnetic 

 electrical machine. ' Mr. Clarke's machine,' says Mr. Sax- 

 ton, ' differs from mine only in a slight variation in the situa- 

 tion of its parts.* Every scientific inquirer knows what an 

 amazing difference a slight variation in the situation of 

 parts will often occasion in a philosophical instrument. But 

 to proceed, he continues to say that my instrument is in no 

 respect superior to his. I have already pointed out a few facts 

 to prove that it is superior, and shall, ere I conclude, convince 

 your readers that it is in every respect to be preferred. All 

 I can expect, all I ask for is fair play. Let the public witness 

 what Mr. Saxton's machine can do, and all that it can do, 

 next witness the effects produced by mine, and then let them 

 decide which they prefer. 



" I shall now proceed to another assertion of Mr. Saxton's, 

 viz., that no description of his machine had been published 

 previously to the insertion of his attack upon me. Why, a 

 description appeared in the number of the Mechanics' Maga- 

 zine for May the 3rd, 1834; again, in Sir Richard Phillips's 

 work, printed in 1834; again, by Mrs. Somerville; and also 

 in the Catalogue of the Adelaide-street Exhibition : what, then, 

 is Mr. Saxton's meaning? 



" Let us now examine a little more minutely into the real 

 facts of the matter as connected with the construction of the 

 machines. By Mr. Saxton's own showing (fig. 3) the cy- 

 linders A B, on which the wires for the shock are coiled, are 

 of the same size as the cylinders C D, round which the short 

 wires for giving the spark are coiled. My principle is totally 

 different. Different as regards the size of the cylinders (those 



