866 Mr Barlow on the Dcvelopement of' Magnetism by Rotation. 



led to those that form the subject of his paper, were so total- 

 ly unlike my experiments, begun in 1819, and continued in 

 the construction of my correcting-plate to the present time, 

 that " no latitude of language" will admit of the former being 

 considered as a repetition or extension of the latter. 



He also considers his experiments on the attraction of the 

 iron shell, published in the Camb. Trans, to be " quite un- 

 connected"" with my experiments just before completed on the 

 same apparatus ; and lastly, that his idea of referring the po- 

 sitions of a ball, by means of an imaginary sphere circumscrib- 

 ing the needle, is quite original and independent of my idea 

 of referring the position of the needle by means of a sphere 

 circumscribing the ball ; and so completely independent, that 

 he not only omits all reference in these cases himself, but ob- 

 jects to such reference being made by others. 



On the other hand, he maintains that the connection be- 

 tween the phenomena due to rapid rotation, and those which 

 he had observed, was so obvious, (although it had never oc- 

 curred to him during the four years he had the subject on 

 hand,) that notwithstanding I have, in the first page of my 

 paper, stated my knowledge of his experiments, and that his 

 results had encouraged me to proceed with the idea I had in 

 view ; and notwithstanding I waited five months for him to 

 complete his paper before I sent my own, yet after all this 

 I have, in his opinion, so very inadequately made my acknow- 

 ledgments that he felt himself, in consequence, justified in 

 adding a chapter on this new class of phenomena to the very 

 paper for which the delay had taken place, without noticing, 

 in any manner whatever, either my experiments or the ac- 

 commodation. 



On all these points it is clear Mr Christie and I entertain 

 very different opinions, and both of us probably very consci- 

 entiously. It will therefore, I conceive, be best to leave the 

 subject with the explanations which have been offered on both 

 sides to be decided by less interested judges ; and, in order to 

 prevent the necessity of any farther discussion, I have avoid- 

 ed offering any comments upon Mr Christie's last letter ; but 

 there are one or two points of minute criticism, by which some 

 parts of my former letter are represented as erroneous, which 



