124 



THARDWICKE'S SCI E N CE- GOSSIP. 



time, during which the various atmospheric agencies 

 have worked in producing the scenery of the dis- 

 trict is question, we shall presently return, but I 

 think we may fairly conclude that our second question 

 has been answered thus : — Atmospheric agencies may 

 produce our scenery as a whole, given sufficient time. 

 If this be so, we are led to inquire in the next 

 place, How far the effect of these agencies is varied 

 by the peculiarities of the rocks in structure and com- 

 position ? We have already seen that in a general 

 way different kinds of rock are associated with 

 different kinds of scenery, and we now wish to 

 examine more minutely into the scenery, and to 

 observe tlie causes, not only of the general style of 

 architecture, but of the varied carving and orna- 

 mentation. 



We will commence our study round what I can- 

 not but consider as the gem of the English Lakes, 

 Derwentwater. We stand at the end of Friar's 

 Crag, that rocky promontory jutting out into the 

 lake. Before us are spread the glistening waters, 

 with here and there a well- wooded isle. Due south 

 is the entrance to Borrowdale, at the head of the 

 lake. On our left — the east side of the lake — are 

 the steep craggy mountains forming Wullow and 

 Ealcon Crags, and the rocky precipices about Low- 

 dore and as far as Grange. On our right — the west 

 side of the lake— are the generally smooth grassy 

 mountains of Swinside and Cat Bells, and many 

 others of similar nature on either side of and 

 beyond the beautiful inverted arch of Newland's 

 Tale. Nothing could be more distinct than the 

 mountain-forms on either side the lake ; on the one 

 hand all is rough and craggy and the outline 

 rugged, on the other all is smooth and sloping and 

 the outline soft". And why is this ? The c.aise is 

 not far to seek. On the east side of the lake the 

 mountains are formed of hard volcanic rocks, which 

 are constantly being shattered by the weather and 

 fall away in large blocks, sometimes of great size, 

 strewing the ground below. Numerous irregular 

 joints and fissures assist in the work, and hence the 

 craggy hill-sides. On the west side, however, the 

 material is very different, the mountains are formed 

 of Skiddaw slate, which instead of breaking away 

 in laro-c fragments, shivers into small scales or 

 pencil-like pieces. The waste of these hills is not 

 found upon their slopes or at their base in the 

 form of large blocks like those of a ruined castle, 

 but in that of a fine clayey and shaly wash of com- 

 minuted slate. We see at once that the atmospheric 

 agencies are at work lowering the mountains on 

 eitiier side, but the same agents working on dif- 

 ferent materials produce a very different result. 



But now, having mastered the general features 

 of this view, let us, as we in imagination walk 

 round the lake, note some of the miimtiaj of the 

 scene. And first let us observe our standpoint, 

 Friar's Crag, and the round craggy and wooded 



hills of Cockshot and Castle Head. These are all 

 formed of greenstone intruded among the Skiddaw 

 slates ; the latter are soft;, the former is hard ; 

 hence the craggy prominences ; and Friar's Crag 

 owes its special character, as the horn of a small 

 bay, to narrow greenstone dykes among the softer 

 slates. 



Next I wish you to observe that the line of 

 junction between the soft Skiddaw slates and the 

 hard volcanic series runs along the eastern edge of 

 the lake, and that that line is a faulted one. The 

 hollow in which the lake lies has been scooped out 

 of the softer rocks. Now carry your eye along 

 the craggy line of mountains rising above and 

 behind Barrow House. Here there are many 

 alternations of stratified ash-beds and lava-flows, 

 all dipping slightly into the hill at a low angle. 

 The consequence of this is that a step-like form is 

 given to much of the upper part of this hill-side, 

 some of the beds being harder than others, and 

 more or less standing out in relief, and from the 

 opposite side of the lake especially these parallel 

 lines of strike form a very conspicuous feature. 



Walking southwards from Barrow House, one is 

 much struck with the great quantity of material 

 fallen from the steep rocky cliffs, and the large size 

 of some of the masses, all, it would seem probable, 

 brought down by weathering since the close of the 

 glacial period. Behind the Borrowdale Hotel is 

 the beautiful comb of Frontdale, a patch of grassy 

 and cultivated land running up among the craggy 

 mountains. Examination shows that the bottom of 

 the comb is formed by the soft Skiddaw slates, and 

 the sides by the hard volcanic rocks. Upon the 

 other side of the road lies the alluvial land at the 

 head of Derwentwater, representing a part of the 

 lake filled up by the matter rolled down into it 

 by the river Derwent and the Lowdore stream. 

 Soundings taken in the lake show how this fiUing- 

 up is still going on, for a long stretch of shallow 

 water, from six to nineteen feet, runs from the 

 present mouth of the Derwent full three-quarters 

 of a mile out into the lake, having deeper channels 

 on either side. 



Arrived at the picturesque village of Grange, we 

 reach the southern limit of the Skiddaw slates, and 

 on entering Borrowdale have around us on all sides 

 rough wild craggy mountains with strangely hum- 

 mocky outline, formed of cleaved volcanic ash 

 and breccia, with occasional beds of contempora- 

 neous trap. The bedding of the ash is often very 

 evident, as along the face of Gate Crags (fig. 75) and 

 on many smaller rock exposures, the prevailing dip 

 being S.S.E. at from 25° to 30°. The planes of 

 cleavage crossing this dip at a higher angle often- 

 times strike the observant eye very forcibly, while 

 in some places the frequent joint planes give oc- 

 casionally somewhat of a columnar appearance even 

 to the well-bedded ashes. But, perhaps, the most 



