RevieiDS — Prof. J. Beete Jukes's Letters, etc. 567 



the older Palseozoic rocks, he says, " I had once been working hard 

 for about five weeks, trying to understand and delineate on the one- 

 inch map a complicated bit of mountain ground a few miles south of 

 Conway, in North Wales. It was made up of interstratified slates, 

 sandstones, and felstones, with large and irregular masses of in- 

 trusive gTeenstone, the exposed parts of each being frequent, but 

 not continuous. Many a weary day had I climbed the sides, and 

 clambered along the crags of a hill, some five or six miles in length, 

 by two or three in breadth, and the highest peak of which was not 

 more than 1,800 feet above the sea, trying in vain to reduce to order 

 the seemingly endless complexity of its structure, and having at 

 length on the map as curiously complex a patchwork of incongruous 

 colours and unnatural forms as Punch, had he turned geologist, 

 could have devised ; when one evening, as, after a hard day's work, 

 I was descending a steep bit of ground, almost in despair at all my 

 labour seeming to be thrown away, I hit upon the clue to a great 

 fault or dislocation. I had only time then to verify the observation, 

 but it gave me at once the solution of all the puzzle ; and in two or 

 three days I was enabled to map the whole district, with as near an 

 approach to accuracy as the scale of the map admitted of. The 

 country was chopped up by a series of large parallel faults, that 

 were quite easy to be seen when once the clue to one of them and 

 its bearings were obtained, but which there was nothing to render 

 a priori probable, and which could not have been discovered without 

 that thoroughly exhaustive process of examination which I was 

 enabled to apply to the district. I have ever since regretted that, in 

 my haste and joy at acquiring a right notion, I obliterated all my 

 former work from the map which contained it ; for I should have 

 been glad to preserve it now as a curious instance of the contrast 

 between laborious hypothesis and the simplicity of natural truth." 

 (pp. 306-308). 



Speaking of Coal-mining, Mr. Jukes says, " Very few people are 

 aware of the enormous amount of loss which has been incurred, and 

 is even yet of annual occurrence, in fruitless mining enterprises." 



■' Sedgwick, on a visit to Sir H. Halford, in the south part of 

 Leicestershire, saw an engine, etc., at the top of a hill a few miles 

 off, and was told it was a coal-pit. He naturally went to look, and 

 on going up the hill found Lias shale with Lias fossils, etc. ' Why,' 

 says he, ' this is Lias ! ' ' Lias ! ' says the proprietor, coming down 

 on him ; ' You're a liar, and you're all liars together ! ' etc. Natu- 

 rally the man ruined himself." 



The stories of two equally futile explorations are given in the 

 Geological Magazine for November last (pages 500 and 505). 



"In South Staffordshire (says Mr. Jukes), I knew two instances 

 of ground bailiffs, intelligent men, well versed in ' coal-getting,' 

 continuing to sink in Silurian shale, and heaps of the fossils of that 

 formation lying on the pit bank ; they were still going down for 

 coal." 



" The name of these stories is legion. The money wasted in this 

 century, for want of the very rudiments of geological knowledge in 



