published respecting Aiitnin, Deny, Isfc. 291 



most of the strata * ; but for which, I should not despair if 

 on the spot, of tracing ihe eastern edge of the Basaltic 

 trough, from where Mr. D. 1( aves it E ut Lisburn, in a S or 

 SW direction to the SE coast of Down, or that of Louth : 

 to find again its western cd^e on that Coast, and trace it 

 thence in a NW or NN\V direction to Slieve-Gallon 

 M luntain W of Desmartin in Derrv, where Dr. R. satis- 

 factorily describes its edge, vol. xxxiii. p. 202, and Anp. 23, 

 and thence NNW to Solomon's Porch at the NW corner, 

 where I began. It is true, Dr. R. (App. p. 2i') mentions 

 a strip of Basalt about three miles broad, extendina" near 

 to the middle of Armagh County at Market- hill and Gos- 

 ford Casiie, in such term?, as might have led me to sup- 

 pose, that white limestone appeared from under the sides 

 of tliis projecting horn of Basalt j had not Mr. D. p. 373, 

 ii/brmed us, that an official docuirient of the fri:-h Parlia- 

 ment states, that " from Blackwater town (down the Black- 

 water River) to Lough Neagh, and from (hence again up 

 the River Bann, and along the Canal to Newry (an extent 

 of nearly 30 miles) there is no Iwiestone ivhatever ;" al- 

 though the line of navigation from Lough Nvagh to Newry 

 must twice have crossed the trreat Liinestone basset, had not 

 its unbroken plane, in all this length, laid deep buried un- 

 der Basalt, with Gravel locally distributed on it, as the 

 " whynstoiies on the surface," Mr. D. p. 39, and the 

 *' field-stones," Dr. R. App. p. 22, give room to suppose; 

 but when Dr. R. returns northward (not southward, p. 23) 

 in describing the western edge of his Basaltic area, and 

 says, it" crosses Lough Neagh diagonally, catches the Derry 

 shore not far from Ballvronaii ; the Basalt is found in- 

 cumbent on ^vhite luDestonc at Spring Hill." A difficulty 

 arises, and lam unabh to follow him, for want of any Map 

 \yhich shows either, the two las' places or Magheraiin, men- 

 tioned in the preceding page (ami p. 277 herein) ; or to orain 

 satisfaction, as to whether Limestoveajiy where appears on the 

 shores 0/ Lough Neagh P and under what circumstances? I 

 should suppose it does not, both iromwhat Dr. D says p. ]59, 

 as well as the document above quoted, whose object was, 

 to show, the necessity of a Canal to the Blackwater Naviga- 

 tion at the Town of Moy, which, were it '* opened from 

 Armagh, it must necessarily go through Lands in that vici- 



•. Since the above was written. Dr. Richardson informs us (Agricultural 

 Magazine, vol. x. p. IS.-;; that " on the south side ot Lough Weagh, tha 

 country i-: for ten miles long nnd six brond a deep flow bog, with a liumber 

 of islands" thinly scattered over it, called Derrys; are these islands cum. 

 posed of basali ? or of grit srone, shale &e. belonjfing to the co.al-measures J 



Vol. 39. No. iCd. Jprll 1812, T nity. 



