382 • Koike respecting Neto Books, 



our party called its revetement ; I adopt the word on ihw 

 occasion for convenience. 



After we had traced the dyke eastward for several yards, 

 we observed this revetement separate from it, and diverge 

 at a considerable angle, then, forming a curve, disappear 

 beneath the sand to the north-east; this new circumstance 

 exciting our attention, we traced the revetement back, to 

 the dyke, then along it to the westward, when after -^ome 

 time we perceived, it entering the dyke at an acute angle, 

 and crossing it diagonally ; when across, it formed for se- 

 veral yards a revetement on the south side of the dyke, then 

 diverging from it, and curving as before, it was again lost 

 under the sand to the south-west. 



The second dyke I will describe particularly, lies about 

 500 yards north from the silver stream, and about three 

 miles from Carrickfergus; it seemed composed of four or 

 five distinct walls, agglutinated together; in each of these 

 the prismatic construction was dilferent from that of the 

 others, and in one the axes of its prisms were not as usual 

 at right angles, but oblique to the ihrection of the dyke. 



A new circumstance occurt'ed here too ; this dyke, about 

 25 feet broad, had a revetement of freestone on each side, 

 and was also twice or thrice penetrated by walls of freestone 

 similar to, and in the same direction with, the basalt walls 

 between which they lay ; these freestone walls were more 

 than a foot broad, and sometimes composed of horizontal 

 laminae, and at others of vertical. 



I have since discovered a magnificent dyke in the face of 

 the stupendous precipice of Cave hill* which it cuts verti- 

 cally near 200 feet, and is afterwards to be traced a great 

 way down the hill. 



Though this dyke be attended by very curious circum- 

 fttances, I will take no further notice of it, as I hope to see 

 it soon accurately described by my ingenious friend Dr. 

 McDonald, who was with me when i discovered it, and 

 whose vicinity affords him better opportunities of accurately 

 examining this beautiful and interesting fa9ade. 



LVIIT. Notice respecting New Books. 



A. NEW edition of Dr. Henr)''s chemical work is in the 

 press, and will be published in the course of a few weeks* 



* A stratified basaltic mountain, nearly hanging; oYer Belfast; it is well 

 worth Uie attem.ion of natiiralisw. 



