Page:Popular Science Monthly Volume 6.djvu/655

Rh have been in the ground previously, and been quickened by the deposit of the mud. Mr. Meehan thought that perhaps the seeds of these plants, protected from air while buried under water, might germinate after exposure to the air. He referred to other cases of the springing up of new plants after the deposit of fresh earth, and suggested a mode of testing the origin of the seeds.

Education and Invention.—There exists a very general belief that great inventions usually come from uneducated men. How erroneous this belief is, at least as regards the art of metallurgy, is well shown by Mr. G. F. Becker, in a lecture delivered in the College of Mines, University of California. Nasmyth, for instance, invented the steam-hammer, without which neither the metallurgist could turn out sound masses of metal of sufficient size for the fabrication of the vast machines now in use for steamships and other purposes, nor the machinist forge them into shape. The crystallization process, and the zinc process for the decolorization of lead, not only enable us to extract at a profit very small proportions of silver and gold, but also produce an admirable quality of lead. Formerly the quality of lead used to depend almost entirely on that of the ore, and the best brands were exported to all parts of the world; now the best of lead may be made from almost any lead-ore. The inventor of the crystallization process, Pattison, was a professional assayer and metallurgist; and Karsten, who invented the zinc process, was a man of great learning and a metallurgist of the first rank. The inventor of the Rachette furnace, "the furnace of the present and probably of the future for lead or copper smelting," is the engineer who controls the whole governmental smelting and mining interests of Russia. Bessemer, the inventor of the process which bears his name, is a man of extensive scientific acquirements; and Siemens, whose most ingenious apparatus for producing very high temperatures has vastly increased our powers of heating iron and steel, of producing all grades of steel, and of distilling zinc, received as perfect an education, scientific and technical, as the world had to offer. It was Faber du Faur, an accomplished Bavarian metallurgist, who first made practical use of the gases which formerly escaped in immense quantities from the tops of blast-furnaces; and the enormous blast-engines, the hoisting-engines, pumps, and hot-blast stoves, often even the roasting-kilns of such establishments, nowadays require no fuel except this long-neglected waste product. Bischof, another engineer, and metallurgical author, was the first to produce gas artificially for smelting purposes; and this was one of the greatest advances ever made in metallurgy. Lundin, a thoroughly educated Swedish metallurgist, has shown how gas may be produced from wet saw-dust, of such power that wrought-iron may be melted with it.

The Temperature of Germination.—Herr F. Haberlandt has published three tables, showing the maximum and minimum germination temperature of all the more important agricultural seeds. He gives the minimum for by far the largest number, including wheat, barley, rye, oats, buckwheat, sugar-beet, linseed, poppy, clover, lucern, peas, rape, and mustard, as below 40.5° Fahr. The minimum for sainfoin, pimpinella, carrot, cumin, sunflower, Sorghum saccharatum, S. vulgare, and maize, is between 40.5° and 51° Fahr.; for tobacco and gourd, between 51° and 60.4° Fahr.; and for cucumber and melon, the minimum lies betweeenbetween [sic] 60.4° and 65.3° Fahr. The second table shows the percentage of seeds germinating at the temperatures 61°, 47°, 88°, 100°, 110°, and 122° Fahr., and the number of hours elapsing before the rootlets reached a length of two millimetres (0.07874 inch). The maximum limit for coriander and marjoram is between 77° and 88° Fahr.; for wheat, rye, barley, oats, English ray-grass, vetches, horse-bean, peas, chick-peas, white-mustard, woad, cabbage, late kohl-rabi, turnip, radish, madder, fennel, carrot, cumin, parsley, poppy, linseed, tobacco, and anise seed, between 88° and 100° Fahr.; for the common bean, lupin, clover, lucern, early kohlrabi, summer-rape, buckwheat, chiccorychicory [sic], sunflower, and some varieties of cabbage, between 100° and 110°; and finally, for maize, Sorghum vulgare, panic-grass, turnip-radish, hemp, teasel, gourd, cucumber, and sugar-melon, between 110° and 122° is the maximum. The third table shows the average