94 



THE GEOLOGIST. 



and its only visible effect is the charring of the coal, which it divides 

 in Durham, and the ordinary results of intense heat upon the con- 

 tiguous shales, limestones, and sandstones. Its width is from 

 seventeen to about sixty feet, and is greater in the middle than at 

 its two extremities. Its depth, it need not be added, is unfathonable. 

 When unaltered by weather it is of a dark blue colour ; but owing to 

 the iron which it contains, the outer portion becomes rusted upon 

 exposure, and exfoliates like an ironstone. An excellent view of this 

 " frolic of nature," as it has been called, may be seen in a cutting 

 which the railway has made through it near Castleton, and its caustic 

 effects on the bordering strata for a very short space on each side, and 

 total absence of dislocating fracture may be clearly observed. Owing 

 to its intense hardness, it is of invaluable utility as a material 

 for the roads to a great distance on each side of it, for which it would 

 otherwise be a difficulty to find a stone sufficiently durable. It is, 

 and when the proposed lines are completed will be much more, exten- 

 sively wrought, and sent to a great distance to pave the streets of 

 several of our large towns. 



There are many instances .of alluvial deposits, and many isolated 

 granitic boulders at the foot of Carlton Bank, at Lealholme Bridge, 

 and other places, which I cannot now stay to remark upon. With 

 reference to the vast superficial accumulations of peat at Danby End 

 and other places, I shall quote an extract from a work published 

 about eighty years ago,* as an illustration of a geological theory 

 at that period, and at the same time to impart a piece of interesting 

 information for any " Judeeus Apella" of the nineteenth century: 

 " Hazel-trees and nuts with kernels in them are found in our peat- 

 bogs, covered up most probably by the deluge ; and I cannot help 

 observing here, that these nuts prove to a demonstration that the 

 flood of Noah happened in the autumnal season of the year, and 

 most probrably in the month of September, when it is known that 

 kind of fruit is always ripe with us here in Yorkshire." 



I may here observe before, before I conclude, that there are traces 

 to be noticed, at Furnace Farm, near Fryup End, in Commondale, at 

 Castleton, and other places, of the rude manufacture of iron in 

 ancient times. At the above places are large heaps of scoria3, from 

 which the metal has been but imperfectly extracted, and amongst 

 which I have found pieces of the metal itself. These primitive iron- 

 masters, who lived most probably in monkish times, seem from the 

 small pieces of ore which I have found to have merely collected the 

 loose boulders; or outside pieces of the thin rich nodular bands, and, 

 of course, used charcoal only, as may abundantly be seen, in their 

 reduction to a fluid state. 



It now merely remains for me to express my regret at not being 

 able within the scope of this essay to dwell, as I should greatly have 

 wished, upon the characteristic and other fossil-remains of the 

 several groups ; and to express the obligation I am under to the 



* Hist, of Whitby ;" by L. Charlton : 1779, p. 353. 



