Page:Popular Science Monthly Volume 37.djvu/733

Rh the crooked stick while it is still hot and inserts it in a notch cut in a stout board, placed at an angle inclined from him," where he bends and strains it. When it has become perfectly straight it is thrown down to cool, after which it becomes rigid and permanent in its lines. Heat is an important element in this matter, and produces different effects on the several kinds of wood, the degree of heat necessary to straighten one kind of stick being often sufficient to spoil another kind. The same power which makes a crooked stick straight is applied to make a straight one crooked; so we find that the rigid stems of bamboos, partridge canes, and all the various kinds of sticks that are required to be curled or twisted, are by the application of heat made to assume almost any shape or form. Thus we often see ladies' sun-shade handles twisted and even tied into double knots. By far the largest number of sticks used are those known as natural sticks—that is, saplings of trees or climbing plants, when the roots have sufficient character to form handles or knots. These are always more in demand than sticks cut from solid wood. The finished canes are sometimes mounted with precious metals, stones such as onyx, jasper, marbles, even precious stones, ivory, and horns of all kinds.

Microscopic Structure of Stone.—The investigation of the minute structure of minerals and rocks is recommended by Dr. H. Hensoldt as the application most eminently adapted to afford pleasure and satisfaction to the lover of the microscope. It presents an exceeding complexity of forms and a most wonderful display of colors, and offers a field as yet almost untrodden and affording endless opportunities for research. "Especially striking and lovely is the appearance of many of the volcanic or igneous rocks, when reduced to thin sections, and examined under the microscope. The dullish green lava, called pitch-stone, which is found in dikes on the island of Arran, on the west coast of Scotland, exhibits under the microscope whole forests of fern-trees, garlands, leaves, and flowers of marvelous magnificence. A certain granite from Cornwall contains needle-shaped crystals of tourmaline, radiating star-like from a common center. Basalts, obsidians, porphyries, serpentines from various localities, show labyrinths of multicolored crystals resembling rows of pillars, turreted castles, and fairy caves, glowing in all the tints of the rainbow. The sedimentary or stratified rocks, while they can not under the microscope equal their Plutonic rivals in brilliancy of color or gorgeousness of crystalline display, make up for this deficiency by other features of interest, compensating the inquirer with revelations of a different character, but none the less remarkable. Many marbles and limestones are found to be literally composed of foraminifera, the tests of rhizopods, resembling tiny shells of the most delicate and beautiful forms. . . . Thin sections of almost any piece of flint exhibit under the microscope quite a little world of curious organic remains, such as sponge spicules, xanthidia, small fragments of coral, and the foraminifera already mentioned, furnishing very strong evidence that the flints are silicified fossil sponges. . . . This branch of study, though barely thirty years old, has already contributed such a vast deal of new information to natural science that it has, in more than one respect, revolutionized our old-fashioned conceptions of geological research."

Asphalt in Building Construction.—Some interesting examples of recent new uses of this substance are given in a paper with the above title by Mr. T. H. Boorman, published in Architecture and Building. The writer says: "From the cellar to the roof, asphalt has been used where the requirements have been water and fire proof floors. Its principal merits are its utter imperviousness to water or damp, and its elasticity, whereby cracking, especially from the influence of frost, is prevented. Also from a sanitary point of view the advantages of asphalt are incontestable, for it possesses great antiseptic properties, and, owing to its having no joints, it is impossible for particles of animal or vegetable matter to lodge in crevices and putrefy. It greatly promotes cleanliness, as it can be easily washed, and for this reason is invaluable in hospitals, breweries, stables, etc. Asphalt first appears in your specifications as under the item of 'damp course.' It is advisable to lay throughout the walls on the grade of the cellar-floor half an inch