qfOie Planet Vesta. 251 



time of the opposition, as the latitude was decreasino- ; or it 

 may be also affected by not having apphed the same parallax 

 in the reduction : the refraction was probably the same in both 

 cases ; the mean of which, in my Tables, agrees with those of 

 the French. 



Blackheath, April 18, 1823. S. Groombridge. 



LVI. Observations on the Experiments of Mr. Murray, on 

 tJie supposed Relation between Caloric and Magnetism. By 

 An Experijienter. 



To the Editors of the Philosophical Magazitie and Journal. 



T^HE curious fact mentioned by Mr. Murray in the last 

 Number of the Philosophical Magazine, first, I believe, 

 occurred to my son, a boy about nine years of age. He had 

 been in the habit of accompanying me while making experi- 

 ments on various philosophical subjects, and amongst the rest 

 some on magnetism and electro-magnetism. One day I found 

 hun anxiously waiting my return home, to inform me of a dis- 

 covery he had made, which was precisely that of Mr. Murray. 

 He told me that he had "found out that flame attracts the 

 magnet ;" and on his repeating the experiments before me, I 

 must say that I was at first "much astonished. But having 

 learned from long experience to doubt the accuracy of hastv 

 conclusions, I advised him to make the trial on a small piece 

 of zmc wire which happened to be at liand ; and on repeating 

 the experiment, he obtained precisely the same results as be- 

 fore. The cause of the apparent magnetic action of the flame 

 on the needle was now obvious: it was evidently only the 

 current of ^air produced by the heat of the lamp that caused 

 the motion in question; and if Mr. Murray will take the 

 trouble to make the experiment here indicated, he will find 

 tjie same results. 



Yours, &c. 

 Colchester, April 2, 1S23. An EXPERIMENTER. 



P' S. — It should have been observed that we did not make 

 Mr. Murray's last experiment: if it had occurred to us at the 

 lime, it would have been difficult to have performed it, with-- 

 DUt burning the silk by which the needle w^is suspended. 



I i 2 LVIl. On 



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