102 



HARBWICKE'S SCIENCE-GOSSIP. 



[k.) S. vulgare, supra-lincatum. Frond thick, 

 coriaceous, and dark green. This varies so much 

 that it is difficult to give a correct description ; the 

 margin is cut and dentate, whilst the epidermis on 

 the upper side is wrinkled, giving it a withered ap- 

 pearance. Lancashire, Scotland, and Wales, not 

 unfrequent. 



(/.) S. vulgare, laceratum. A fine variety, giving 

 the whole plant an exuberance seldom seen in 

 cultivated ferns, although it is variable in habit. 

 The fronds are sometimes dwarf, but almost as broad 

 as long ; the margin is irregularly and deeply lobed 

 and incised, the apex is often cut and crisped, if not 

 as often branched, so that it becomes a dense tuft of 

 bright green miniature fronds. Found in Devonshire 

 and Ireland. 



Besides the above, there are many other equally 

 distinct varieties. The above are from specimens in 

 our own herbarium. An excellent inducement to 

 seek the hart's-tongue varieties is in the fact of 

 their easy cultivation, they will grow well in a 

 rockery, in any court or back-yard, without the aid of 

 fern cases or greenhouse. An excellent plan is first 

 to cultivate them for a time, thus many varieties turn 

 out permanent forms of great value. 



OUR MOUNTAINS, AND HOW WE CAME 

 BY THEM. 



By the Rev. J. Clifton- Ward, F.G.S., &c. 



No. II. 



IN the last number we considered the various 

 theories which might be suggested to account 

 for the origin of our mountains, and came to the con- 

 clusion that they were neither due to the individual 

 upheaval of the masses, so that any bedded rocks enter- 

 ing into their composition would be thrown into a rude 

 dome ; nor to their being separate cases of igneous 

 intrusion through and above an original plain ; but 

 that the hills, as we now see them, owe their being to 

 removal of surrounding matter, in other words the 

 mountains exist because, and in spite of denudation. 

 It will however shortly be seen that although the 

 direct cause of the separate mountain masses may be 

 the removal of matter by physical agencies, yet this 

 could not have taken place without a general upheaval 

 of the whole district, and a gradual bringing of the 

 various rocky deposits within the reach of the denu- 

 ding agencies. 



Having made these preliminary remarks, mainly for 

 the purpose of giving a more intelligent and lively 

 interest in what immediately follows, we now proceed 

 to examine into the character of the matter composing 

 the mountains, endeavouring to discover under what 

 conditions that matter was formed or laid down. 



First, it must be remarked that the Mountain 

 District and the Lake District are not co-extensive. 



Almost all the true mountains of the district he to 

 the north-west of a line drawn in a very straight 

 course from the north-west side of the estuary of the 

 Duddon, by the heads of Coniston Water and Win- 

 dermere* to Shap Wells (see rough map, fig. 61). This 

 line we shall see is formed by a definite geological 

 horizon. On the south-east side of it there lie the three 

 lakes of Coniston, Esthwaite, and Windermere, and 

 the country though not mountainous, is still very hilly 

 and much cut up by valleys, often narrow and deep, 

 draining to the south. Upon the north-west side of 

 this line the traveller cannot fail at once to notice the 

 change in the character of the scenery, for bold moun- 

 tains almost immediately confront him, and this is 

 especially the case in the immediate neighbourhood of 

 Coniston, where the true mountain region begins pre- 

 cipitately almost like a huge rampart or wall. Walk- 

 ing northwards from this point, many a bold mountain 

 peak is seen, and many a scarped face, and it is not 

 until the country on the west side of Derwentwater, 

 and the Skiddaw range are reached that the rugged 

 and cliffy forms give place to mountains of a softer 

 outline and smoother slope. Among these we will 

 begin our studies of mountain-matter. 



As a general south-west and north-east line divides 

 the truly mountainous district on the north, from the 

 hilly country on the south, so a line having a very 

 similar direction, about six miles north-west of the 

 former, parts the mountains formed of Skiddaw slate 

 from those formed of rocks of the Volcanic series (see 

 map), or in other words, parts the softer outlined 

 mountains from the more rugged. We only recognise, 

 in passing, this dependence of mountain-form upon the 

 geological structure and material, meaning to devote 

 more time to this part of the subject when we are 

 better prepared by a general survey of the history to 

 grasp the true meaning of the facts which Lake 

 District rambles present. The southern boundary of 

 the Skiddaw slate mountain district is, however, a 

 very zigzag line, running from a little east of Egre- 

 mont, first generally eastwards, then northwards to 

 Ennerdale, then eastward again to the head of the 

 Buttermere Valley, north-eastwards to the head, and 

 east side of Derwentwater, and eastwards once more 

 to the conglomerate hill of Mell Fell. On the north 

 the Skiddaw slate is overlapped by the carboniferous 

 limestones, or by rocks belonging to the Volcanic 

 series. There are three other small areas where the 

 Skiddaw group of rocks is met with, these are, 

 a tract skirting a considerable part of Ullswater, 

 another to the west and north-west of Shap, and 

 thirdly Black Comb north of the Duddon estuary. 



The formation derives its name from Skiddaw, one 

 of the finest and most conspicuous mountains composed 

 of rocks of this age. On Skiddaw, indeed, the rock 

 is slaty, and so in many of the other mountains, but 

 the formation is by no means universally slaty, and 



* In this case a little south of the absolute head. 



