Vol. 59.] EXPERIMENT IN MOUNTAIN -BUILDING. 349 



from the second. The ridges are narrower, shorter, more pre- 

 cipitous, and more broken up. This characteristic is not, however, 

 very well brought out in the photograph. The intervening spaces 

 form wide, flat valleys. 



In another experiment sand .and layers of baize were arranged 

 as before, but the weight was placed on one side, in consequence of 

 which the material was more easily pressed up. 



In this case the ridges followed the edges, though not closely, 

 leaving a central hollow. Here, also, in the upper layer of cloth (fig. 5, 

 p. 352) the slopes were more gentle, the eminences more rounded, 

 the hollows less deep. In the second layer of cloth (fig. 6, p. 352) 

 the country is more rugged, the elevations higher, the hollows deeper. 

 Here too several of the ridges have a tendency to become double, 

 with in some cases a smaller ridge commencing in the depression. 

 The elevations and hollows only follow roughly those of the upper 

 layer. There are two main ranges, with a broad intermediate 

 valley. One of the main ridges has secondary transverse folds. 



The third layer (fig. 7, p. 353) again has only a general resem- 

 blance to the second. The folds are more numerous, narrower, and 

 more precipitous. 



The fourth or lowest layer (fig. 8, p. 353) presents a central plain, 

 bounded by two high, one moderate, and one low, series of hills. 



The models seem also to show that some hollows, which might on 

 the earth's surface have been regarded as evidence of sinking, are in 

 reality only relative, and due not to depression, but to the elevation 

 of surrounding ridges. 



I am proposing to make further experiments with various modi- 

 fications, which at some future opportunity I hope to be permitted 

 to lay before the Geological Society. 



Discussion. 



The Chairman (Mr. E. T. Newton) said that the fact that the 

 subject of the paper was one to which the President had given so 

 much attention, would all the more cause the Fellows to regret his 

 absence and the reason that gave rise to it. 



Mr. Hudleston disclaimed any special knowledge of the subject, 

 but wished to draw attention to a particular feature shown in 

 the models, which, as he understood the Author, had been men- 

 tioned in his explanation. This was the more acute accentuation 

 of the foldings in the lower part of the series. So far as his (the 

 speaker's) experience extended, this peculiarity might be noticed 

 in certain mountain-ranges. There is an excellent example in part 

 of the Jhelum Valley in the Outer Himalayas, where all the beds 

 are of one formation, namely, Middle Tertiary, and where it is easy 

 to perceive that the lower beds, close to the river, are often vertical 

 and extremely contorted, while higher up the angle of inclination 

 lessens, and towards the top there is a simple anticline of moderate 



