136 Proceedings of the Royal Irish Academy. 



LOCALITY OF OCCURRENCE. OBSERVATION . 



Sandyford. — 



Lough Shinney Coast. — 



Feltrim Quarry. — 



Number of Directions observed, 6. 

 285" 30' 4- 6 = 47° 35' W. mean value. True bearing, 68° 55' W. 



No. of 



Magfnetic 



Jointing 



Bearing. 



261 



47° 30' W. 



262 



45° 30' W. 



263 



49° 30' W. 



449 



47° 30' W 



556 



48° W 



558 



47° 30' W 



503 



38° 



W. 



Palmerstown 



606 



38° 



w. 





507 



37° 



w. 





510 



41° 



w. 





511 



40° 



w. 





512 



40° 



w. 





514 



41° 30' 



w. 





433 



34° 30' 



W. 



434 



33° 30' 



W. 



435 



32° 30' 



w. 



502 



34° 30' 



w. 



Number of Directions observed, 7. 

 275° 30' 4- 7 = 39° 21' W. mean value. True bearing, 60° 41' W. 



Drumanagh Promontory. 



Palmerstown. — 



Number of Directions observed, 4. 

 135° -^ 4 = 33° 45' "W. mean value. True bearing, 55° "05' W. 



400 27° 30' W. Donabate Coast. — 



425 27° 30' W. „ „ — 



426 29° W. „ „ — 

 432 26° 30' W. Drumanagh Coast. — 



439 28° 30' W. Lough Shinney Coast. — 



440 28° 30' W. „ „ „ — 

 456 29° 30' W. Skerries Coast. — 



492 26° W. GoUarstown Bridge. — 



493 28° 30' W. „ „ — 

 519 28° 30' "W. Lucan. — 

 544 28° 30' W. Feltrim Quarry. — 



Number of Directions observed, 11. 



308° 30' -Ml = 28° -02' W. mean value. True bearing, 49° 22' W. 



355 25° 30' "W. Malahide Coast. 



378 24° 30' W. 



380 24° 30' W. 



422 23° 30' W. Eush Coast. 



