Page:Popular Science Monthly Volume 45.djvu/593

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working of the Livèt furnace appears to depend upon the peculiar construction of its flues, which are so built as to utilize the effect of the decreasing volume of the gases of combustion traveling toward the chimney, so promoting a high velocity to the air passing through the furnace bars and producing rapid combustion with intense heat. At the same time, the effect of this peculiarity of construction is to cause the gases themselves to move slowly through the flues, so that they may part with their useful heat before escaping into the atmosphere. The force of draught at the furnace is such that a high and constant temperature is obtained and efficiency of combustion insured, while all unpleasant odors inherent in town garbage are destroyed. As an example of the heat economy effected, it is said that whereas in previous, generators the best results ever obtained have been three quarters of a pound of water evaporated on the combustion of one pound of refuse, in the Livèt generator over three pounds of water are evaporated into steam for every pound of refuse consumed, in spite of the fact that it is frequently known to contain twenty per cent of moisture. The temperature of the gases just before entering the chimney is stated to be from 300º to 400º Fahr. lower than hitherto obtained. The progression of the gases is partially arrested at both ends of each flue for the purpose of permitting them to deposit the contained light dust in suitable expansion chambers or pits which can be cleaned out when desirable. This arrangement serves to overcome the objectionable dust, which in ordinary "destructors" tends to choke the flues and impregnate the ah-of the surrounding districts.


Uses of Drinks.—In discussing the question whether Australia will become a wine-drinking country. Dr. Murray Gibbs pointed out that different nations had always, from time immemorial, selected certain beverages as national drinks, and that the fact that the fruit, leaf, or grain supplying the essential principle of the drink was not always indigenous to the national soil was itself a proof that convenience was not the only factor indicating the choice. Many continental nations drink, of course, the wine of their particular district, and for centuries the Englishman's beer was made from the Englishman's barley. On the other hand, the universal vogue of drinking decoctions made from the Eastern shrubs tea and coffee shows that the popularity of a beverage has no geographical limits. The character of the drink adopted as national must always be largely dictated by the character of the soil and food, and this, in turn, is dependent upon the climate of the country. Sir William Roberts has said that all beverages, alcoholic or non-alcoholic, conduce to one of two conditions—retardation of the digestive process or excitation of the nervous system. The harsher climates require the stronger foods, and these—inasmuch as time is necessary for their proper assimilation—call for checks upon a too rapid and so incomplete digestion. Chief among these are the vegetable acids contained in wine, and the sedative properties of tea and coffee.


Occupations to awaken Dormant Faculties.—In a paper on Industrial Training in Reformatory Institutions (published by C. W. Bardeen, Syracuse, N. Y.) Mr. F. M. Briggs, of the State Industrial School, relates a few incidents of cases in which mental powers, before dormant, were awakened by setting pupils at work for which they had a taste. "There are boys in the State Industrial School at the present time," the author says, "whose interest we could not arouse in the common schools. Some were naturally so weak mentally that after weeks of conscientious work on the part of the teacher, they were not able to repeat from memory a four-verse stanza of a poem for children. Others would not apply themselves sufficiently long to learn anything. Some of these boys were placed in the clay-modeling and wood-carving shop. The boys who had been regarded as almost idiots soon began to show improvement. The boys who had been especially troublesome elsewhere, in the clay work ceased to be annoying. When a boy begins work with clay, he seems to feel himself in the unity of things and he becomes happy accordingly; and, as he sees the formless clay take shape beneath his touch, a sense of power is born within him which arouses and quickens him." A boy who had been cruel, cunning, and vicious, presenting no point for reaching his nature, one day in the wood-working shop