My dear Sir,

I came home last night and found two letters from you: tonight I receive a third.¹ The interest you express in the terrace subject is very gratifying to me, and I am happy to do all in my power to gratify it. I have been at Belleville²—you will be breathless with expectation. Well, I shall be quite candid with you. It is a district of Strathspey,³ full of grand unmistakeable river terraces. Near Belleville, a burn comes down, with an intersected half ruined delta, as usual, of which nothing can be made for my purpose, as there is no hitting a true sea line in such cases. Two miles back on the face of the brown hills, are two lines like those of Glenroy, but extending only a short way. I do not know if they be what Sir David B. meant⁴ —probably not, as they are not less than 1500 feet above the sea—indeed Belleville house itself is 800 at least. Uncertain if these were meant, seeing no means of ascertaining their height to any nearness, and unwilling to give the day which would have been necessary for the attempt, I did not pause upon them. The river terraces, however, I studied with some care, and I measured some lines near Kingussie⁵ up to about 1400 feet above sea. Amongst the river terraces there was one unusually conspicuous and well defined. A great promontory of it starts across the valley above a place called Nuid. It is like a captain among his men. Well, taking the railway levels for all but about 150 feet of the height, I made this terrace in what I thought its upper parts, seen from a distance, 869 feet; just 8 below the lowest Glenroy shelf. I think it very likely if I had been on it, and examined the part towards the hill side, which represents the sea surface of its age, I might have found it fully 877; but I was content to bring away my notes without immediately arguing how the result should tell in relation to Glenroy. There can be little doubt this terrace is a memorial of the same sea with that which formed the lowest of the Glenroy roads. The only other linear appearance on which I can lay great stress was made by me 998 feet, being 11 above a measurement I have noted of the lower Glen-Gluoy terrace (found also by me in Glen Spean), and somewhat nearer to another measurement of the same done by Mr Milne. Here there is not enough of precision to found upon; yet it is remarkable. There are lines of the Glenroy character on the hills in many parts of Strathspey, and I suspect Sir D. B. has particularly referred to Belleville and Phones, only because he is necessarily familiar with these places as parts of his sister-in-law’s estate (that of Ossian Macpherson).⁶ Miss Macpherson knew nothing of them. Upon the whole I am not quite pleased with my investigations in Strathspey; but I must plead being hurried home by business considerations.⁷ The great difficulty in these cases is to get right bases to start from. On this occasion I had the plans of the Perth and Inverness railway; yet was much at a loss. As to Loch Tulla,⁸ I have a series of terraces there more numerous than Mr Milne’s, and an engineer has promised me the exact height of the lake above the sea, which will enable me to say if they coincide. I fully expect they will, for I am now at that point when all discord with one leading idea is shut out. I am not unobservant of glacier action— I see traces of it as the history of an age antecedent to that of the gravels and terraces. Everything like a supposition that glaciers can have made the Glenroy or other terraces appears to me like a dream. I would as soon believe that Julius Caesar established our trial by jury. The terraces and gravels are all over the till or drift which is connected with the glacier period. The hill of Unichan,⁹ instead of being a moraine, is the delta of three or four strong glen burns coming from the neighbourhood of Ben Nevis. Tour-na Fersit¹⁰ and other masses near Loch Treig are the remnants of the delta of the Laire burn which comes down through them and joins the Spean near Inverlaire house. The top declines away from near that burn towards the south and east, as might be expected. Having extended to the opening of Loch Treig, it has made a barrier there, so as to form a lake, now cut down a hundred feet from its original height. I now see all these things as clearly, I think, as if I had been present when they were going on in fact—and they will form a curious addition to physical geography. Excuse me then from entering into any discussion with you about the glacier theory. I leave it aside as part of a different section of the geological history from mine, though adjacent to it. Do also be so good as correct yourself as to any ideas I may with all humility have formed as to the means of the shift of level. Though I see difficulties as to an uprise of the land in the case in question, I have ever treated it as an open question. With our as yet imperfect knowledge, who can speak positively on the subject?

I admire your enthusiasm in wishing to have the head of Strathspey surveyed. I do not know any young man who could be got to work cheap at such a task, but I feel anxious to get one to take a few levels for me in that district, and may yet be able to help you to your wish. However, having never found anything off the horizontal in hundreds of observations with the level in all parts of Britain, I feel sure you will discover no inclination in this instance. Mr D. Stevenson¹¹ has now given me exact statements of the intervals of the Glenroy terraces—212.37, and 80.32 feet. My own memorandum of the interval to the upper Glen Gluoy was “fully thirty”, though Mr Milne says 29. The upper Glen Roy being now strictly 1170, I would make the upper Glen Gluoy just a little above 1200. The following is the tabular view of these terraces, with their relations.¹² diag Lochaber Tweed West Lomond, Fife. 1202(?) 1203 1170 1162 1090 1087 989 L^r. Gl. Gluoy 987

&c &c 877$\frac{1}{2}$ 877 765–72 (new) 766 765. ramme all the usual terraces under 500 feet being likewise found in Lochaber—a splendid series at Fort William.

Believe me, my dear Sir, | most sincerely yours, | R. Chambers.