Page:Popular Science Monthly Volume 28.djvu/883

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regular part of the routine. The fields are left from time to time for three or four years, by rotation, in grass. In the summer months, female servants, or the daughters of the farmer, tend the cattle high up in the field, living in sæters or cabins, where they prepare cheese and butter. But this isolation of the young women is sometimes attended with serious moral disadvantages.

The Coral-Harvest.—The most productive coral-beds, which also yield the best and handsomest corals, are on the Algerian coast, and have been fished upon since the middle of the sixteenth century. Other beds are on the coasts of Sicily, Sardinia, Corsica, Spain, the Balearic Islands, and Provence. More than five hundred Italian vessels, with 4,200 men, are engaged in the coral-fishery, and collect annually 56,000 kilogrammes of coral, the value of which is calculated at 4,200,000 lire ($840,000). Besides these, 22,000 kilogrammes, worth 150,000 lire ($30,000), are collected in French, Spanish, and other boats, making the whole annual product 78,000 kilogrammes, and its value 5,700,000 lire ($1,150,000). The taxes which the Government exacts for the privilege of fishing on the African coast amount to 1,160 lire a boat in the summer and half as much in the winter, and this, taking into consideration the toil and danger of the fishery, reduces the profits to a quite modest rate. Estimating the gross returns per boat at 8,000 lire, and the cost at 6,033 lire, we have a net profit of 1,967 lire ($393.40). There are some sixty establishments in Italy where coral is worked up, forty of which are in Torre del Greco, and at which 9,200 hands, chiefly women and children, are employed. The principal markets for the coral are Germany, England, Russia, Austria, Hungary, and Poland; and considerable quantities are sent to Madras and Calcutta.

Advantages of Low Ceilings.—Rooms with low ceilings, or with ceilings even with the window-tops, are more readily and completely ventilated than those with high ceilings. The leakage of air which is always going on keeps all parts of the air in motion in such rooms, whereas if the ceiling is higher, only the lower part of the air is moved, and an inverted lake of foul and hot air is left floating in the space above the window-tops. To have the currents of fresh air circulating only in the lower parts of the room, while the upper portion of the air is left unaffected, is really the worst way of ventilating; for the stagnant atmospheric lake under the ceiling, although motionless, keeps actively at work under the law of the diffusion of gases, fouling the fresh currents circulating beneath it. With low ceilings and high windows no such accumulation of air is possible; for the whole height of the room is swept by the currents as the dust of the floor is swept with a broom. Low ceilings have also the advantage of enabling the room to be warmed with less expenditure of heat and less cost for fuel.


A mine of mercury—consisting of the sulphuret and chloride, with drops of metallic mercury, in a gangue of quartz—which appears to have been worked in ancient times, has been rediscovered at Schuppiustuna, near Belgrade, in Servia.

Additional interest will be given to the coming meeting of the British Association at Birmingham, to be opened September 1st, by the exhibition of local manufactures which is to be held in connection with it. Similar exhibitions have been held on each of the three previous occasions when the Association met in Birmingham, in 1838, 1849, and 1865; and it is said that all of the international and other exhibitions which have since been held had their origin and prime model in the first of these; and that the Great International Exhibition of 1861 was suggested to Prince Albert by his visit to Birmingham in 1849. The coming exhibition will be more extensive and varied than any of the previous ones.

M. E. Rivière has discovered a new station or workshop of the neolithic age in the wood of Clamart, near the gates of Paris. He has recovered from it nearly nine hundred flints (from nodules in chalk), cut or broken by the hand, all of which lay on or near the surface of the ground. Among them are pieces of polished hatchets, scrapers (some very handsome ones), blades, points, and two or three little polishers.

Artificial lithographic stones are manufactured in Frankfort by M. Rosenthal from cement, which is put for the purpose through a course of very careful manipulations.