A word or two about the telescopes themselves will be appropriate here, for they are no ordinary instruments. The one at Nürren is valued at a hundred and twenty pounds. It is a double instrument, and two persons can look through it at the same time. The other instruments depicted in the various photographs are valued at from sixty-five to ninety pounds apiece. They were made by the famous optical firm of Carl Zeiss, of Jena, and represent the last word in telescope construction. Not all the telescopes through which visitors may peep for a small fee on the mountains of Switzerland were supplied by this firm, though there are certainly a large number of them. They are to be found on the Riffelalp, above Zermatt; on the Schynige Platte, near Interlaken; on the Rigi, the Weissenstein, near Solothurn; the Wengern-Alp, on the Jungfrau Railway; at Berne, Grindelwald, and other places. [Illustration: THE FIVE-INCH TELESCOPE AT NÜRREN. _From a Photograph._] Without going into technicalities, it may be added that the instruments are fitted with the new Jena glass, which is perfectly transparent, and, therefore, gives a clear image. In cutting and polishing the glasses every care was taken to eliminate chromatic aberrations, this being of great importance for landscape observations, the image being thus freed from the distracting coloured borders with which every user of ordinary glasses is familiar. The instruments may be roughly divided into two classes: monocular and binocular (_i.e._, those through which the observation is made with one eye only, and those through which it is made with two). The former are mostly fitted with a revolving appliance, the turning of which allows of a rapid change of magnifying power. The object glasses in these instruments vary from four inches to five inches in diameter. The four-inch instrument magnifies objects thirty-five, fifty-three, and seventy-three times, according to the turning of the wheel, and the five-inch glass instrument thirty-five, fifty-eight, and a hundred and sixteen times. The binocular instruments are contrivances astonishing in their effect. It is well known that our power of perspective rapidly decreases as the distance from the object increases. The reason of this is that the facial angle at which objects appear decreases with the distance, and finally becomes so slight that we lose all power of estimating it. We can, however, enlarge this angle by approaching the object, or by bringing it apparently near to us. This is accomplished in these five-foot telescopes by the employment of an artificial medium, so that separate objects in a landscape view twenty miles distant--houses, trees, people, etc.--appear as if they were only eighteen yards away. The effect is wonderful and charming. Mountain peaks and wooded valleys, which when seen through an ordinary telescope are all apparently on the same plane, stand out sharp, clear, and in glowing natural colours.