Page:Popular Science Monthly Volume 10.djvu/397

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383
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more economical of fuel. The experiments appear to have been successful. The engine one day was worked as an ordinary condensing engine, when it was found that the consumption was 1,116 pounds of coal in six hours, producing an indicated horse-power of 84.747. The next day the engine was driven with Marchant's steam-pumps connected with the low-pressure cylinder; the consumption of coal was now 1,158 pounds, while the indicated horse-power was 104.123. The ascertained work on the steam-pumps was six indicated horse-power.

 

Gathering Rock-Crystals.—Searching for rock-crystals is one of the recognized industries of the Swiss Alps, and the men who follow this vocation are known as Strahlers. The following notes upon the search for these crystals we take from the Moniteur Industriel Beige: The outfit of a Strahler consists of a bar of iron four feet long and bent at one end, a shovel, a pick-axe, a hammer, a stout cord, and a leathern sack. Thus equipped, he goes out to his work in the morning. He nearly always goes alone, so as to have all he may find for himself. For hours and hours he creeps along the sides of the rock, on projections of a few inches, over yawning chasms. When he descries a vein of quartz, he strives to reach it, but oftentimes this is a matter of extreme peril, and involving much labor; he must be very careful where he steps, and not seldom he must hew out a resting-place for his foot in the rock. Having reached the vein, he follows it and strikes it with his hammer. His practised ear tells him whether he has to deal with a "cavern," a "druse," a "pocket," or a "kiln," as the various kinds of cavities are called in which are found the crystals—whether attached to the walls or loose and mixed with sand. The most famous discovery ever made of monster crystals is of very recent date. Some hundred feet above the snow-line an apothecary of Bern saw a vein of quartz 60 feet long and from 4 to 1.2 feet wide. On working the vein, four hundred-weight of crystals were taken out; the larger masses were purchased for museums, while the smaller pieces were sold to opticians.

 



NOTES.

The chemical laboratory for female students, in the new building adjoining the Massachusetts Technological Institute, has been thoroughly fitted up, and was occupied for the first time early in November.

Five specimens of ground coffee, chemically examined by C. H. Eddy, of Michigan University, were found to be adulterated to the extent of from 22 to 39 per cent, with chiccory. One package, labeled "Pure Mocha and Java," contained 23 per cent.; "Pure Rio," 25 per cent.; "Pure Java," 22 per cent.; "Royal Java," 31 per cent.; "Warranted pure government Java," 39 percent. Besides chiccory, these prepared coffees consisted chiefly of peas, oats, starch, carrots, etc. In three of the five specimens no caffeine could be discovered.

White-lead, as a pigment, is chiefly valued for its "body," and for the ease with which it is laid on; but it produces lead-poisoning, and also tends to lose its whiteness. Zinc-white is not open to these objections. Properly prepared, it has as good covering properties as white-lead, and the addition of magnesia in the manufacture makes it as easy to work; besides, it has no injurious effects on the health of those who manufacture or use it.

An extensive deposit of plumbago has been discovered in Longswamp Township, Berks County, Pennsylvania. "The deposit," says the American Manufacturer, "is between seven and eight feet in depth, and the mineral is of the best quality. Similar deposits are supposed to exist elsewhere in the same region, and persons are now engaged in prospecting, but as yet no new discoveries have been made."

The Library Table for November contains a good sketch of the life and works of Mr. Darwin, with portrait. A valuable feature of this periodical is its classified index to current periodical literature.

The death is announced of the eminent French geologist, Charles Sainte-Claire Deville, at the age of sixty-two years. He was a native of the island of St. Thomas, graduated from the Paris School of Mines, studied the geology of the Antilles, and published the results of his investigations in 1856. Later he was Professor of Geology in the Collége de France. For many years he devoted himself to the study of meteorology, and to him in great measure is due the foundation of the Montsouris Meteorological Observatory.

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