British Association. 119 



ment of Abel Intelligible to beginners, and even to advanced students 

 in algebra. The constitution of most minds was such that they 

 were anxious to run away from those subjects on which their labours 

 could be profitably employed, and to engage themselves in the pro- 

 secution of curious and sometimes almost useless difficulties. He 

 exemplified the celebrated resolution of the Academy of Sciences of 

 Berlin, that they would in future receive no more communications 

 on the subject of squaring the circle, as a remarkable proof of the 

 extent of this morbid state of mind ; for it was a fact that the average 

 number of communications on this subject, when taken for many 

 years, amounted to four annually. The rage for resolving mere al- 

 gebraic difficulties was pretty much the same, and he, therefore, for 

 one, felt that the gratitude of men of science was due to Sir W. 

 Hamilton for thus giving an <$;?non argument, the obvious tendency 

 of which was to save the laborious exertion of talent in fruitless re- 

 search J a labour, for the employment of which such vast regions 

 were at present opening before us in rich profusion. As it occurred 

 to him, the chief advantage which he expected from the method 

 adopted by Sir W. Hamilton was this : that whereas from its very 

 intricacy the argument of Abel would be inaccessible to the ordi- 

 nary algebraist, and a doubt therefore would always remain on his 

 mind of the validity of the conclusion, and consequently he would 

 be tempted even still more strongly to essay the difficulty for him- 

 self, — the method of Sir W. Hamilton, besides making the principle 

 and many of the steps of the argument intelligible to all, and there- 

 fore giving a high degree of probability to the conclusion, has this 

 peculiar advantage; that by applying the very same mode of arguing to 

 quadratic, cubic, and biquadratic equations, it has not only proved 

 that they are soluble by precisely the modes by which we at present 

 resolve them, but it proves further, that they are insoluble by any 

 other purely algebraic device. This seems to be conclusive, and 

 must carry conviction to every mind. 



Sept. 13 — Prof. Lloyd read an " Account of the Magnetical Ob- 

 servatory now in course of erection at Dublin." 



In bringing this subject under the notice of the Section in its pre- 

 sent stage, Mr. Lloyd said, that he trusted little apology was required. 

 The establishment of permanent magnetical stations has been urged 

 by the powerful recommendation of the British Association ; and he 

 was sure that that body would view with interest the progress of 

 an undertaking, the importance of which was sanctioned by its au- 

 thority. 



The magnetical observatory, now in progress at Dublin, is situated 

 in an open space in the gardens of Trinity College, and sufficiently 

 remote from all disturbing influences. The building is forty feet in 

 length, by thirty in depth. It is constructed of the dark-coloured 

 argillaceous limestone, which abounds in the valley of Dublin, and 

 which has been ascertained to be perfectly devoid of any influence 

 on the needle. This is faced with Portland stone j and within, the 

 walls are to be studded, to protect from cold and damp. No iron 

 whatever will be used throughout the building. With reference to 



