Page:Popular Science Monthly Volume 29.djvu/879

Rh down suspended matter, is greater in a large body of water than in a small one. It will be better, however, to err on the side of too large an amount, for even then the amount of alum added will be insufficient to impart any detrimental properties to the water. The water, after precipitation has taken place, is perfectly clear and sparkling, and has acquired neither taste nor smell. For use in the dye-house no possible objection can be made to it.

The Story of India-Ink.—India-ink is of comparatively late introduction in Europe. It was a rarity in the middle of the seventeenth century, and a record exists of a stick of it being preserved along with some "giants' teeth"—mammoth bones—as a curiosity, in the Museo Moscarda, in 1672. The Chinese, however, assign a great antiquity to its use in their country, and name, as the inventor of it, Tien-tchen, who nourished between 2697 and 2597 About two hundred and fifty years  balls were made of lampblack from fir-wood, lacquer, and size. A poet of that day, singing of this precious material of his art, mentions with especial praise the ink that was made of the firs from the hill-side of Lou-Chan, in the province of Kiang si. This province was celebrated for the fine quality of its ink, which was at one time made under the supervision of an hereditary government officer as overseer. A number of sticks of the ink were sent every year to the emperor as a tribute. There were illustrious names among the Chinese ink-makers. The most famous of them was Li-ting-Kouei, who not only made his sticks of a quality which has become proverbial, like that of the Stradivarius violins, but molded them into a variety of quaint and artistic forms, and received a special honor from the emperor. During the long history of the Chinese-ink, a great variety of processes have been employed in its manufacture, and nearly every kind of combustible has been used for the production of the lampblack. That resulting from the combustion of petroleum is said to make a more brilliant and blacker ink than that made from fir-wood. The size by which the particles of the lampblack are held together is frequently of animal origin, being made from the bones of the stag, rhinoceros, and ox, and from various kinds of fishes. The Chinese instruments of writing have been assigned supernatural guardians, whose places of precedence are settled by strict rules of etiquette. The "Prefect of the Black Perfume" is the official style of the ink-deity, and he is of higher rank than the divinities of the pencil and the paper. It is said that, a very long time ago, this divinity appeared to the Emperor Hiuan-Tsong while he was writing, and announced to him that henceforth, when a man of true learning or genius should write, the twelve deities of ink should make their appearance to testify to the reality of his powers. It is said that the twelve deities of ink have never appeared since.

Periodicity of Cyclones.—Mr. Charles Meldrum, in continuation of his observations relative to his theory of the periodicity of cyclones, which he believes to occur in cycles corresponding with the eleven-year cycle of sun-spots, has published the results of the meteorological observations which he has systematically compiled from the logbooks of vessels traversing the Indian Ocean for the nine years 1876-'84. The observations averaged forty-six for every twenty-four hours included in the review. By the aid of these records nine cyclone-charts have been prepared, one for each of the years, and these, together with the twenty that had previously been prepared for the years 1856-'75, show, as far as has yet been ascertained, the tracks of the cyclones of the Indian Ocean south of the equator in each of the years 1856-'84. The tracks for the years 1848-'55 are nearly ready. With respect to the period 1876-'84, the areas of cyclones and the distances traversed have not yet been determined, but, upon the whole, the number and duration of the cyclones decreased to a minimum in 1880, and then increased till, in 1884, they were more than double what they were in 1880. From the accompanying track-charts for the eleven years, 1856, 1857, 1860, 1861, 1867, 1868, 1871, 1872, 1879, 1880, and 1884, it appears that the number and duration of the cyclones of 1856 and 1857 were much less than those of the cyclones of 1860 and 1861;