[ 107 ] 

 XII. On Magneto-electric Induction. By F.Watkins. 



To Richard Phillips, Esq., F.E.S. #c. 

 My dear Sir, 



HAVING lately observed in the Philosophical Magazine 

 some descriptions of slight modifications of apparatus for 

 the development of magneto-electrical phaenomena, and pre- 

 suming from their insertion that you think such contributions 

 interest your readers, I venture to offer to your notice an 

 account of a philosophical apparatus, or toy, which I have 

 contrived, and which I believe to be novel. 



The production of motion by magneto-electricity is not 

 new, many philosophers having already suggested and pre- 

 pared various mechanical contrivances by which a body might 

 be made to move continuously by magneto-electric agency. 



Among the contrivances with which I am acquainted, none 

 can vie, either in simplicity or in beauty of design, with that 

 which emanated from the ingenuity of Mr. Saxton. The in- 

 strument as originally constructed by him may be daily seen 

 in operation at the Gallery of Practical Science in Adelaide 

 Street. 



Having been, as you know, for a long time extensively en- 

 gaged in the construction of electro-dynamic and magneto- 

 electrical apparatus, on seeing Mr. Saxton's machine, I, with 

 his permission, immediately commenced making one nearly 

 after his fashion, and afterwards conceived that it might be 

 made to show an increased number of phaenomena. Following 

 out my ideas experimentally, I obtained distinct revolutions 

 from eight magnetic needles, together with the vibration of a 

 ninth. I am not aware that a multiplication of motion to 

 this extent has been achieved before ; indeed, by applying a 

 second electro-magnet seventeen bodies might be put in mo- 

 tion at the same time, and by a judicious arrangement even 

 more. 



The drawing which accompanies this communication re- 

 presents my apparatus. In arrangement it varies very little 

 from that of Mr. Saxton's, the difference being merely in this 

 respect, that Mr. Saxton places the axis which carries his 

 main revolving permanent magnet outside of the electro-mag- 

 net, while my axis is situated inside. The only advantage 

 I obtain is that the apparatus is much more compact. Were 

 this all I have to advance on the subject, I should not trouble 

 you with the present communication ; but as I have added 

 seven permanent magnets in different situations, and succeed- 

 ed in obtaining continued rotatory motion in all, I conceive 



P2 



