The civilised world will be astounded to learn that the ultimate cause of trolling, systematically practised, was none other than Mr. Gladstone. He was staying at Butterstone, in Perthshire. Mr. George Curzon, afterwards Viceroy of India, also was visiting in the neighbourhood. He was exceedingly anxious to have a Tay salmon to present to Mr. Gladstone. Naturally, therefore, he called in the help of Mr. Malloch. Fish being plentiful in the river at the time, Mr. Malloch led Mr. Curzon forth with confidence. To make quite sure of success, he broke his use and wont by taking with him a few minnows and prawns. Instead of beginning with flies, Mr. Malloch and Mr. Curzon began with minnows. They fished over the best of the water without having a touch. Then they tried prawns. Prawns were of no use. The day ended, and a salmon for Mr. Gladstone had not been caught. Much vexed, Mr. Malloch set about seeking the cause of failure. It occurred to him that the explanation might lie in the temperature. This surmise was strikingly justified. It is morally certain that Mr. Curzon's ambition would have been fulfilled if, instead of trying minnows and prawns in their eagerness, Mr. Malloch and he had used flies. The scientific warrant for this assertion is best stated in a note with which Mr. Malloch has favoured me. "The temperature of the water," he writes, "was 60°. I have taken temperatures ever since, and now know why we failed. With the water at 60° it is a waste of time to try minnow or bait of any kind. With the temperature above 50° fish do not take bait well; fly is much more deadly. I never now think of using a bait until the temperature is under 50°. The following is from my Diary for ten days after it occurred to me that temperature was the explanation:-

Water 47°,

7 fish with prawn ; raised 6 with fly ; lost 2.

„ 47°,

10 fish with prawn; none with fly.

„ 51°,

2 fish with prawn ; 4 with fly.

„ 46°,

6 fish with prawn; 4 with fly.

„ 46°,

the same day another angler fishing behind me took 5 with spoon.

„ 51½°

, 2 fish with prawn; 1 with fly.

„ 50°,

2 fish with prawn; 3 with fly.

„ 51°,

none with prawn; none with fly.

„ 50°,

2 with prawn ; 3 with fly.

„ 46°,

3 with prawn; 2 with eel tail; none with fly.

" Every day the fly was used in the morning and the prawn in the afternoon; the same water was fished in succession. Had I stuck to the fly when the water was above 50° I should have done better. I do not mean that fish will not take bait when the river is at a higher temperature; but I do mean that only an odd'fish can be caught when it gets near 60°. We can catch fish in tLe Tay all spring with bait until about May 15, a few between that and the end of the month, and almost none in June and July.

"During the last six years the average temperature of the Tay during May was 48.4°; June 53½°; July 59.4°; August about the same as July. Sometimes the weather is so warm in September that fish will not take a fly."