on the deep and narrow valleys.
How very singular the fact is which you mention about the inclination of the strata being greater round the circumference than in the middle of the island; do you suppose the elevation has had the form of a flat dome? I remember in the Cordillera being OFTEN struck with the greater abruptness of the strata in the LOW EXTREME outermost ranges, compared with the great mass of inner mountains. I dare say you will have thought of measuring exactly the width of any dikes at the top and bottom of any great cliff (which was done by Mr. Searle [?] at St. Helena), for it has often struck me as VERY ODD that the cracks did not die out OFTENER upwards. I can think of hardly any news to tell you, as I have seen no one since being in London, when I was delighted to see Forbes looking so well, quite big and burly. I saw at the Museum some of the surprisingly rich gold ore from North Wales. Ramsay also told me that he has lately turned a good deal of New Red Sandstone into Permian, together with the Labyrinthodon. No doubt you see newspapers, and know that E. de Beaumont is perpetual Secretary, and will, I suppose, be more powerful than ever; and Le Verrier has Arago's place in the Observatory. There was a meeting lately at the Geological Society, at which Prestwich (judging from what R. Jones told me) brought forward your exact theory, viz. that the whole red clay and flints over the chalk plateau hereabouts is the residuum from the slow dissolution of the chalk!