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XVIIJ. Experimental Inquiries concerning the Laws of Magnetic 

 Forces. By WILLIAM SNOW HARRIS, Esq. 



(Read April 1828.) 



1. AN the following investigation, it has been my endeavour to 

 elucidate some of the complicated phenomena observable in all 

 the known operations of Magnetic Forces : The labours of so 

 many profound inquirers in this important department of physical 

 science, are indeed such as almost to discourage those less gifted 

 with similar powers of research from engaging in the same pur- 

 suit ; but knowledge is progressive, and the splendid researches 

 which have displayed the highest efforts of genius serve rather 

 to assist than to deter others in more humble endeavours to pro- 

 mote the advancement of science. 



2. Many excellent writers have well observed, that, to arrive 

 at a perfect knowledge of the laws of magnetic action, we should 

 have it in our power to submit magnets and ferruginous bodies 

 to the test of experiment, but that the combined effects which 

 these forces exhibit have at all times rendered such experiments 

 very difficult and precarious ; so that it has been almost impos- 

 sible to obtain from them simple results. 



3, It may not therefore be altogether useless to describe an 

 instrument calculated to obviate some of the difficulties which 

 have thus impeded the efforts of experimentalists in their endea- 

 vours to investigate the laws of magnetic forces, in which, by the 



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