From Daniel Mackintosh   21 November 1880

Dear Sir,

I am much obliged by the receipt of your kind letter of the 13th. I admit I was writing rather carelessly when I spoke of earthquakes as a geological cause in my last letter.¹

With regard to changes in the level of the sea, the existence of shelly beach deposits at between about 1,100 and 1350 f. in mountain districts at a considerable distance from each other (as for instance, the Wicklow hills, Moel Tryfan, S. of Minera (Denbyshire) and above Macclesfield) would certainly seem to be better explained by the surface of the sea being higher than by the land being lower; but I have found it better not to complicate the subject by entering much into this question.²

I have not read of any geologist having noticed the shattered rocks under the drift of Moel Tryfan excepting yourself.³ I have seen them twice, at different levels in the new quarries, and you must have seen them in the old at a lower level. I look upon them as the most remarkable phenomon connected with Moel Tryfan, excepting the discovery of sea-shells.

With many thanks, | I am Dear Sir, | Your obliged & faithful Servant, | D. Mackintosh.

P.S. In the new or upper quarry sections, there is clear evidence of the floating ice having come from the N.W. or from the N. of Ireland.