Page:Popular Science Monthly Volume 57.djvu/14

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4
THE POPULAR SCIENCE MONTHLY.

from May 15th to June 15th in each of the three years 1897, 1898, and 1899, for the morning hours of the eclipse—between 8 a. m. and 9 a. m. A tabular form was sent through the local offices to such observers as were willing to act as volunteers in making these records, and their reports have been studied to discover how the cloudiness behaves along the eclipse track at that season of the year. Each of the three years gives substantially the same conclusion—namely, that there is a maximum of cloudiness near the Atlantic coast in Virginia, extending back into North Carolina, and also near the Gulf coast in Louisiana and in southern Mississippi, while there is a minimum of cloudiness in eastern Alabama and central Georgia. The following table will serve to make this plain:

 

The Prevailing Cloudiness of the Sky along the Eclipse Track.

State General sky. Sky near the sun.
Virginia 40.3 38.0
North Carolina 32.4 29.9
South Carolina 26.4 24.9
Georgia 16.4 14.7
Alabama 18.2 17.7
Mississippi 30.8 29.2
Louisiana 32.9 27.7
 

The significance of these figures is shown by transferring them to a diagram, given on Chart II, which indicates the average cloudiness prevailing over the several States where they are crossed by the track. The marked depression in the middle portions, especially over Alabama and Georgia, indicates that the stations in these districts make a much better showing than those nearer the coast line. The reasons for this difference are probably many in number, but the chief feature is that the interior of this region, especially over the higher lands of the southern reaches of the Appalachian Mountains, which are from six hundred to one thousand feet above the sea level, is somewhat freer from the moisture flowing inland from the ocean at that season of the year. The table shows also two divisions, one for the "general sky," wherein the relative cloudiness was noted in every portion of the visible sky, and for the "sky near the sun," where the observation was confined to the immediate vicinity of the sun. The two records agree almost exactly, except that the sky near the sun averages a little lower than the general sky. This indicates that although the sun will be seen in the morning hour of May 28th, when it is only from thirty to forty degrees above the horizon, yet this is not an unfavorable circumstance. The low altitude, on the other hand,