WCP4995

[1]¹ [p. 16]

"9, St. Mark's Crescent, N.W., March 9th, 1870.

"Dear Sir,—In accordance with your letter of yesterday, I enclose a memorandum authorizing Mr. Walsh to act in the manner you suggest, which, if you see nothing requiring alteration, please sign and send to him, or if otherwise, write one yourself and send it to me, or send a supplementary one if you have anything to add. With regard to your postscript, I believe you will find that any civil engineer will tell you that the 'decline' you speak of was shown in the spirit-level in the view from both ends—because, on a circle, the place you stand on is always on the top, and in the telescope of the level the signals were always below the level line shown by the cross-hair, and no more could be shown if I went again to the middle station. If, however, the umpire thinks this necessary, he will ask me to show it.

"I remain, dear Sir, yours very faithfully,

"ALFRED R. WALLACE.

"John Hampden, Esq."