SCIENCE-GOSSIP. 



153 



of the dredge into a sieve with coarse meshes which 

 is lying in a slightly larger one of fine mesh. The 

 latter will retain minute organisms which the 

 former allows to pass through. The work of 

 sorting and picking over one haul of the dredge 

 can be done while another haul is being made, if 

 there is a spare hand to do the pulling or to look 

 after the dredge-rope ; but some of the coarser 

 material should be taken home, as curious creatures 

 lurk in crannies. I would strongly advise a resident 



at the sea-side to dredge a small area once at least 

 during each of the four seasons, in order to see what 

 changes may occur at the bottom at stated times. 

 We want what may be termed "natural history " 

 observations of the sea-bottom as well as of the 

 surface of the land. As soon as the dredging season 

 is over, thoroughly wash your ropes and nets in 

 fresh water to remove all the salt and so prevent 

 their rotting. 



(To he concluded next month.) 



THE GIANT'S CAUSEWAY 

 By Charles Wardingley. 



THE geologist who visits the interesting coast 

 between Bengore Head and the River Bush 

 on the north of Antrim must inevitably feel that 

 he has, before and around him, a marvellous 

 example of what can be accomplished by the 

 earth's internal laboratory. The great sheet of 

 igneous rock, of which the Causeway forms but 

 a small part, usually rises abruptly and pre- 

 cipitously from the blue waters of the Atlantic, and 

 lies like a dark shadow overcapping and often 

 burying the various stratified deposits on which it 

 was poured. It is advisable to commence our survey 

 from the water at Benmore Head (Fair Head), 

 a bold promontory twelve miles east of the Cause- 

 way. This cape, said to be the most beautiful in 

 the British Isles, rises from the sea in an almost 



perpendicular cliff to a height of 630 feet. The 

 lower 300 feet consist of carboniferous sandstones, 

 slates and shale, the remainder being made up of 

 basaltic columns, many of which are over 300 feet 

 in length. The carboniferous rocks dip westwards 

 and give place to newer strata, which an ex- 

 perienced eye perceives to be of a cretaceous 

 character. Here, we have a study in black and 

 white, of basalt and indurated chalk, of igneous 

 and aqueous rock, of pillars weathered by atmo- 

 spheric agencies, and of caves worn out of the softer 

 chalk by the ceaseless action of the waves. There 

 again we have "stacks" of basalt rearing their 

 obstinate columns thirty, fifty or eighty feet above 

 high-water mark. 



The shore line gradually decreases in height as 



Photo by] 



The Grand Causeway. 

 H 3 



[R. Welch, Belfast. 



