From the June 22, 1929 issue
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The latest view of the corona, million mile deep outer layer of the sun, is shown on our cover this week. This picture is one of the first to reach the United States from the scientific parties observing the eclipse on May 9. It was made by Dr. R.L. Waterfield, who, with Dr. W.E.B. Lloyd, of Cambridge University, set up a temporary eclipse observatory at Iloilo, near the party from the U.S. Naval Observatory. In the center of the picture is the dark disc of the moon, covering the inner part of the sun, the glare of which ordinarily prevents a view of the faint corona. Since modern eclipse observations have been made, the corona has been seen for a total time of less than an hour, so that its exact nature is still largely a matter of speculation. But it is known to be of very low density, and probably contains some solid particles which reflect the sun's light. Its total brightness is about half that of the full moon. 10 POINT TYPE MOST EASILY READ Large-sized type does not save the reader's time. On the contrary, it is read more slowly by adults than is type of a medium size. This strange conclusion, which is contrary to the supposition of many advertisers, was reached by Prof. Donald G. Patterson and Miles A. Tinker as a result of a test given by them to 320 sophomores at the University of Minnesota. The test material consisted of paragraphs of equal reading difficulty printed in 6 point, 8 point, 10 point, 12 point and 14 point type. All the lines were of equal length, 80 millimeters, and little over 3 inches, wider than the newspaper column. The students' speed of reading was determined for each different size of type, and it was found that the material in 10-point type was read more quickly than either the smaller or the larger type. The difference in number of words read per minute was quite large, especially for the extreme sizes of type. The number of words read per minute from 10 point was 6.2 per cent. greater than from 6 point, 5.2 per cent. greater than from 8 point, 5.8 per cent greater than from 12 point, and 6.9 per cent. greater than from the 14 point. The 10-point type is the size commonly used in well-printed books, and in the SCIENCE NEWS-LETTER. MAYA DENTISTRY Mayan Indians who lived in Central America more than 1,000 years ago practiced dentistry and knew something about the technique of drilling holes in teeth and filling up the cavity with metal. Two teeth containing circular holes filled with iron pyrites are among the significant discoveries reported by J. Eric Thompson, leader of the Capt. Marshall Field Archaeological Expedition to British Honduras, which has just returned to the field Museum of Natural History. |
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