Page:Popular Science Monthly Volume 39.djvu/152

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142
THE POPULAR SCIENCE MONTHLY.

be made of pasturage beyond a reasonable distance from springs. This area is therefore eaten down to the ground, while succulent pasturage beyond it goes to waste. Hardly more than one fifth of the extent of the high plateau, for this reason, is available. Algerian wool is Arab or Berber. Arab wool is generally of a short fiber, sometimes moderately, rarely very long, and regulated as to length by the climatic influences of the localities where the sheep are raised. It is always short on the high plateaus, and becomes longer as the sheep descend into more fertile and better watered regions; but in both instances it is pure wool, of a fine quality, and without any hairy appearance. Berber wool is hard and coarse, and is confined to mountainous and sometimes inaccessible regions, where there is constant pasturage, and the migration of flocks in the summer season is unnecessary.

 

Care of our Eyes. —Few persons are aware, says M. Félix Hément, that besides size, shape, and color, their eyes differ in visual force and in power of accommodation; and also that some faults affect only one of them. It is an established fact that we all use one eye the right or the left in preference, when looking through a glass or taking aim with a gun. We are right-or left-eyed as we are right-or left-handed or footed. If we do not perceive this ourselves, oculists and opticians remark it. The ignorance of most people on this subject is illustrated by their buying glasses at the opticians without taking account of any difference between the eyes. Thus only one of the eyes is helped, while the other one, being less called into exercise, becomes less and less useful, and loses its powers as a tool rusts when it is not in use. Yet both our eyes are needed to see well. It becomes, therefore, highly important to observe how the child uses its eyes, in order to correct those attitudes which tend to injury of the sight as well as of the health. Children, in writing, rarely fail to give the head an inclination by which the eyes are placed at unequal distances from the paper. They are also apt to incline their head too far, and acquire the habit of bringing it too near, as when they try to accommodate themselves to a feeble light. Not sufficient attention, we think, is given to these matters, especially when we consider the consequences of such habits in mature age. A large proportion of our defects originate in want of proper care during childhood. We do wrong to such wonderful tools as our senses when we do not give them the education they need. Is it not surprising that parents who are so particular about the way their children hold their fork or spoon pay so little attention to the way they use their eyes?

 

Stone Chips. —Describing to the American Association the aboriginal stone implements of the Potomac Valley, Washington, D. C, Mr. W. H. Holmes said that they were of soapstone, quartz, and quartzite. The Algonquin peoples quarried the soapstone to get stuff for vessel-making. The quartz and quartzite were made into spear-heads, arrow-points, and knives, and the material was obtained from bowlders dug from the bluffs. In shaping the implements, which was done by percussion, thousands of stones were thrown aside because of flaws. Leafshaped blades were made at the quarries and carried to the villages to be finished. When the village was at the quarry-site, relics of all the stages of progress were found in the refuse. Where the villages were not located on the quarry-sites, no rude forms were found, but only the blades and the fully finished tools made from them. Hence, the author contended, the rude forms of chipped stones are not tools at all; and the difference between the "rough stone age" and the "smooth stone age," insisted upon by French archaeologists, disappears. Mr. Holmes was supported by Prof. Putnam, but Dr. O. L. Mason was not ready to see their theory so summarily disposed of.

 

Our Most Usual Words. —Prof. Jastrow communicated to the American Association a curious study of processes involved in every-day mental life. Twenty-five men and twenty-five women, students in a class in psychology, wrote as rapidly as possible the first hundred words that occurred to them. Of the five thousand words written only 2,024 words were different. Twelve hundred and sixteen words occur but once in the lists. Omitting these, about three thousand of the words were formed by the repetition of only