An Unusual Spectacle—The Explanation—Illustrative Experiment—Looking for Rainbow Trout— A Frost-bound Stream—The Clean Tidiness of the Highlands—What's Wrong with the Cast ?— Strange Beads—An Important Discovery—How Frost Acts on Lakes—"Snow Brew"—Temperature of the Air Unimportant—Still Water and Running Water Show Different Phenomena— Trout Influenced by Varying Temperatures— How These Come About—Sport Suddenly Falls Off—The Explanation, and the Remedy—Trout Prefer the Shallows As a Rule—Do They Sleep ?
In one of the preternatural excursions conducted by M. Jules Verne, there was a pleasing and instructive incident. The explorers came upon a lake in arctic regions. According to all known precedent, the water should have borne a thick sheet of ice ; but it was quite open.
Although the temperature was below zero, there was not so much as a flake or a ray of ice to be seen. Having allowed his companions to gaze for a few moments in wonderment at this spectacle, the leader of the expedition threw a stone into the lake, and produced a spectacle still stranger. As the ripples spread out in a ring round the splash, arrows of young ice darted after and beyond them ; with silent rapidity they darted in all directions; as they flew, the spaces between them were filled up by films ; and within ten minutes the lake had such an attractive surface that the intrepid adventurers were skating.
The explanation is simple. The lake was surrounded by hills preventing a breath of air from striking it; motionless water does not freeze; the energy of nature was liberated in the agitation caused by the thrown stone.
We do not need to go to either of the Poles for proof that this fable is not absurd. Satisfactory evidence may be found in territories that are already within the Empire. Men of science tell of an experiment for which all that is necessary are a tub, a glass with water in it, a few pounds of snow, and a handful of salt. You mix the snow and the salt in the tub ; and they make a thick, briny slush, the temperature of which is much below the point at which water freezes. Then you place the glass in the tub, leaving the rim above the surface of the brine. If the water becomes motionless, it will remain fluid; but in a quarter of an hour, by which time the cold slush has done its work, shake the glass gently, and the water it contains will freeze.
I myself have not been able to succeed with this experiment; but I have twice been a witness of Nature doing strange things with similar materials.
The first occasion was in Fife on a winter morning. The frost during the night had been intense. On getting up and moving about my room, I heard an unfamiliar sound issuing from the earthenware ewer on the washhand-stand. It was not unlike the reedy sigh of a steady quiet wind on the riverside. Shw-sh-sh may represent it. The strange sound was lost in an explosion. The jug had burst at the neck. On examining, I found that the water had become a solid block of ice. Here, as in the incident narrated by M. Verne, the explanation was not far to seek. During the night the water had been chilled below freezing-point; but it had remained fluid because it had remained still. Shaken by my movements in the room, it had quickly congealed ; in doing so it had expanded, and the vessel gave way where its narrowing-in caused the ice to have the greatest pressure.
The other occasion was in the Perthshire Highlands late in February. The journey from London, overnight, had been tiresome, and it was very refreshing to be in the sunlit clean air of the mountains. What was more natural than that, seeing a trout-rod hanging ready in the hall, one should think of a stroll with it after breakfast ? In England you may not fish at that time of the year; but in Scotland, even under the new Act, you may, for salmon. The loch just outside my host's door was ice-bound ; but a mile to the west there was a considerable stream which would surely be open. Many a time I had found excellent sport among the brown trout in that stream ; and it was just possible that now there would be rainbows, three or four thousand of which had a year before been put into the loch, which the river feeds. Rainbow trout, I reminded myself, spawn much later than the native fish: my merry friend, Mr. Douglas Hall, who has some fine ponds, with a considerable stream through them, at Burton Park in Sussex, had assured me that there they remained in good condition until the beginning of March. It would be interesting to learn how the strangers were faring in the Highlands.
The knowledge was not to be easily gained. That became clear when I reached the bridge across the stream about a hundred yards from where it joins the loch. Looking down upon the deep pool under the bridge, I saw scarcely any water at all. The surface was covered with blocks of white ice, apparently thick ; and from the high banks, down the mossy sides of which water had been trickling before the frost, great clusters of huge icicles hung. The cascade just above, which is in three stages, each about twelve feet high, was still in play ; but the water was small amid the encrusting ice. How unlike the appearance of the stream in summer or in autumn ! Then it had been a tawny torrent, often with a flow as good as that of the Test. Now, meandering through the rough masses of snowy ice, it was a blue trickle not much greater than that of an artificial waterfall in a summer garden.
This may seem an odd similitude ; but it is, I think, true. Grandeur of a wild kind is one aspect of the Highlands ; but it is not the only aspect. Even in summer there is about a well-kept estate in that region a beauty which, in one of its many moods, almost dwindles into prettiness. Everything is so clean, and, in the vast expanses, so tidy, that, when just arrived from a town bestrewn with dust or mud, and littered with the vagrant scraps of waste cast upon the streets by the community of millions, one wonders what to do with the match when a cigarette is lit. To be rash with it in this ship-shape place might be like throwing it upon the floor of a drawing - room. In winter, which often lasts until April is well established, this prettiness of the Highlands is intensified. At that time, save where the black crags on the hills are too precipitous to catch the snows, all the towering land is white : dazzling white, if the sun shines unclouded, in the daytime; softly white, if the frost is holding, with a faint rose hue on the irregular peaks, as the shade of the early twilight creeps slowly upward, gray. Also, the Highlands seem smaller. Surely, though it tops all the heights around, that hill cannot be the one up which you toiled, panting, for three hours, in search of a royal red-deer, only six months ago ? Why, it does not seem much more than a mile from the valley to the summit! Surely, too, that depression which you can just make out on the side of the neighbouring hill cannot be the corry by the verge of which one stood in the drive of the mountain hares ? Then it was two miles up: now it looks almost within a cleek-shot! So it is with the loch. Dried up by the frost are all the innumerable rills which in summer made tinkling music, as if of fairy bells, in the tenuous, trembling air; and the loch is low, lower even than normally it is in July, and almost perceptibly narrower; one cannot speak of its length, for both to the east and to the west it winds far out of sight. The few streams which survive the grip of winter are diminished in an even greater proportion.