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November 13th, 1848. 



REV. HUMPHREY LLOYD, D. D., President, 

 in the Chair. 



The Secretary read the following communications relative to 

 recent antiquarian discoveries ; one, a letter from Mr. Richard 

 Young of Island-bridge, accompanying specimens of ancient 

 Danish weapons, discovered by the workmen in excavating 

 near the Terminus of the Great Southern and Western Rail- 

 way. They consisted of a sword, much larger than has been 

 yet found, and a smaller weapon of the same kind, together 

 with an iron spear or pike-head, and a number of iron arrow- 

 heads. The writer stated that he is about opening a gravel 

 pit, which, it is supposed, may contain skeletons and antique 

 remains. There were also presented an iron Roman sword, 

 foynd in a cemetery at Treves, and an ancient urn, dug out of 

 an old wall recently thrown down at St. Audoen's Church, 

 together with some old coins, sent by the Rev. James Howie. 

 A fragment of woollen fabric, worn by the ancient Irish, was 

 presented by Sir Erasmus Burrowes of Lauragh, near Por- 

 tarlington. 



A vote of thanks was passed to the contributors of these 

 interesting specimens. 



Captain Larcom, V. P., having been called to the Chair, 

 the President read a Paper "on the Corrections required in 

 the Measurement of the Magnetic Declination." 



The chief source of error in the measurement of the magnetic 

 declination is that which arises from the torsion of the suspen- 

 sion thread. The angle of torsion appears to be altered, not 

 only by the winding up of the suspension thread, which is oc- 

 casionally necessary, but also by every removal of the magnet 

 itself, the fibres of which the thread is composed appearing to 



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