42 On Local Attraction. [No. 1, 



From the above letter it will be seen, that I come to the conclusion 

 that the earth's crust below the mountains is somewhat less dense than 

 below the plains ; and still less than below the ocean-bed. Mr. Airy 

 {Phil. Trans, for 1854, p. 101) came to the former part of this conclu- 

 sion. But Ms argument requires that the crust should be thin — and 

 so thin as to be influenced for its position by the principles of floata- 

 tion. But Mr. Hopkins' and Prof. W. Thomson's results show that 

 the crust cannot be thin. Moreover Mr. Airy's line of reasoning does 

 not lead to the latter part of the result, in that the crust is more dense 

 below the ocean-bed. For these reasons I have not alluded to Mr. 

 Airy's hypothesis in my Paper. The argument therein explains both 

 these phenomena without requiring that the crust should be thin, but 

 rather the contrary. 



Notes to accompany a Geological map and section of the Lowa Ghur or 

 Sheen Ghur range in the district of Bunnoo, Punjab ; with analyses 

 of the Lignites. — By Albert M. Verchere, Esq., M. D. 

 [Received 10th June, 1864.] 

 Description of the Section, PI. LLI. 



1. Hillocks or morraines formed by the pebbles and boulders of 

 miocene conglomerates and sandstones which have been removed by 

 the effect of the rains : the sand is carried away to the plain, but the 

 boulders and pebbles are left behind and form a morraine. The 

 stones have arranged themselves in layers resting against the miocene 

 beds, with an inclination towards the plain (W) of 20°. 



2. Miocene (?) sandstone, very friable, grey or rather salt and 

 pepper ; calcareous and often so soft that it can be crumbled in the 

 hand. It contains boulders and pebbles, well rounded and worn, 

 generally arranged in bands. It is these boulders and pebbles which 

 form No. 1, as No. 2 is being destroyed. The pebbles and boulders 

 are greenstone, quartzite, quartzose porphyry, gypsose agglomerate, 

 carboniferous and nummulitic limestone, etc. 



3. Similar to 2, but a little harder, and contains occasionally bands 

 of slate in a state of disintegration. Carbonized wood found here, 

 (seldom,) in an iron-stained sandstone. 



