PROCEEDINGS 
OF 
THE ROYAL IRISH ACADEMY. 
1837. Wace 
May 8. 
Rev. F. SADLEIR, D. D., F. T. C. D., Vice-President, 
in the Chair. 
Rey. Thomas M‘Neece, F. T. C. D., was elected member of 
the Academy. 
Mr. Petrie read the continuation of his paper ‘‘ Onthe 
Antiquities of Tara Hill.” 
Professor Lloyd read the following extract ofa letter from 
Mr. Bache, President of Girard College, Philadelphia, re- 
lating to a comparison of the Magnetic Intensity in Philadel- 
phia, Dublin, and Edinburgh : 
“ T availed myself of an opportunity afforded by Professor 
Forbes, to observe the horizontal magnetic intensity at Edin- 
burgh, in a locality as far from the disturbing action of the 
trap rocks, on the north of the town, as was convenient. The 
place (Canaan Park) adjoins that in which Mr. Dunlop’s ob- 
servations were made. After correcting for rate of chrono- 
meter and temperature of needle, &c. I get for Edinburgh 
(Dublin being unity) 0.9592. The dip, as determined by ob- 
servation of Professor Forbes, (and given in a recent paper on 
the diminution of magnetic intensity at different heights,) is 
71° 47’. I applied a small correction for the diminished 
G 
