O'Reilly — On Jointing in EocJxS about Dublin Bay, S^c. 301 



174. 



175. 



176. 

 177. 

 178. 

 179. 



180. 



181. 

 182. 

 183. 

 184. 

 185. 

 186. 



Howlli — continued. 



Loughorecn Hills, mass of rock facing plantation, 

 vertical jointing, in Emitic- 

 looldngrock, with inucli quartz 

 and red oxyde of iron, 

 ,, ,, on top of rock, quartz veins 



nearly vertical, Eiu-itic-look- 

 ing mass, 



Cromlech Dell, jointing runnirig across dell, 

 , , , , another system of joints, 



, , , , cliff side in dell, . 



,, ,, jointing, cutting off north--svest 



point of Muck Rock (passes over 

 summit of Ireland's Eye and 

 Lambay), .... 



Sutton, Dolomites at Sutton quay, life-boat station 

 well- marked vertical jointing, 

 ,, ,, at another point 



on surface of Dolomite, 

 cross jointing, . 

 another system of. 



, , The Dolomite cut off and abutting against 

 decomposed quartzites, 50-60 yards 

 "west of Coast-guard Station. 



187. ,, Coast-guard Station, joiutiag iu slate rock, 



imder flag -staff of, ... . 



188. , , little promontory east of Coast - guard Station 



(near Bottle Quay), the slate much 

 broken and jointed vertically, 



189. ,, quartz veining, very fi-equent here, cuts pre- 



viously mentioned joint nearly vertically, 



190. ,, vertical joint cutting these, not very marked 



191. ,, to the east of last-mentioned point, well 



marked, frequent and vertical jointing, 



192. ,, ,, further east, . 



193. ,, 250 yards west of Martello Tower, great 



joint in slate rock filled with quartz veins 

 indistinct in the true slates, . 



194. ,, about 100 j'ards west of Martello Tower, 



well-marked quartzose veins in the slate- 

 dipping at a high angle north-east, 



195. ,, frequent and vertical jointing, cutting all 



these green slates, 



196. ,, Martello Tower, mass of quartzite, on which 



the tower built, much fissured, west side 



^"i- )) )> !) )) )) )5 



198. South side, Martello Tower, on east side, 12 yards 



from it, weU-marked vertical jointing, 



199. ,, ,, ,, cross jointing, well marked 



and vertical, . 



200. ,, cross jointing, well marked, 



201. ,, (forms the little creek just under Tower), 



202. ,, 60 yards east of tower cave, joint, . 



203. ,, 150-180 yards east of Tower, immense 



jointing, giving rise to a cave, 



5"^. 



67°-68^ E. 



72°-73° W. 



37° E. 

 23=>-24° E. 



37°-38" E. 



36°-37° E. 

 41°-42° E. 

 38°-39° E. 



1 ° E 



6S--69° W. 



3°W. 



6°-7° W. 



21° W. 



60° E. 



70°-73° W. 

 33° E. 



39° E. 

 28° W. 



25°-35° W. 



24° E. 



7°W. 



87° W. 

 82°-85° W. 



90° E. 



4°-5° W. 



43° E. 

 38°-39° E. 

 15°-18° E. 



50° W. 



