«54 KANSAS CITY REVIEW OF SCIENCE. 



From these elements may be deduced the following results : Central eclipse 

 begins at sunrise, in the Pacific Ocean, about one thousand miles west of San 

 Francisco; from this point it will sweep in a northeasterly direction; leaving the 

 ocean it will enter the United States in Latitude 40° North, and cross the north- 

 ern part of California and Nevada, passing over the great Salt Lake of Utah, and 

 through the center of Wyoming and Dakota Territories. It will encounter British 

 America and pass over Lake Winnepeg. Hudson's Bay, and Greenland, and con- 

 tinuing on in the same Hne, it leaves t?he Earth at sunset in the Atlantic Ocean 

 about four hundred miles east of Greenland. 



As seen from Kansas City the Moon will pass too far north to cover the Sun; 

 so we will get only a partial ecHpse, the northern limb and a little over half of 

 his diameter being covered at the time of central eclipse, iih. 55m. A. M. 



The time of first contact or beginning of the eclipse here will be loh. 30m. 

 A. M. , and on the northwest edge of the Sun is where it will first appear. Last 

 contact, or end, will be at ih. 20m. P. M., and on the northeast edge of the 

 Sun. 



In eclipses of the Sun we see no visible effects of umbra and penumbra on 

 the Sun itself. We have the real (though invisible) Moon eating into the real and 

 visible Sun, and along the line named above, there would have been a total cov- 

 ering or hiding of the Sun by the Moon, if its apparent size had not happened to 

 be less than that of the Sun at the time of central eclipse. 



To explain this I must give a few figures. As both Sun and Moon are round, 

 or nearly so, the shadow from the latter ends in a point. The shape of the 

 shadow, is in fact, that of a cone, hence the term "cone of shadow." Now, the 

 length of this cone varies with the Moon's distance from the Sun. When nearest, 

 the Moon will of course throw the shortest shadow. The lengths are as follows : 

 when the Sun and Moon are nearest together 230,000 miles, when farthest apart 

 238,000 miles. The distance from the Earth to the Moon also varies as follows : 

 when nearest together 225,000 miles, when farthest apart 251,000 miles. Hence, 

 when the Moon is farthest from the Earth, or in apogee, the shadow thrown by 

 the Moon is not long enough to reach to the Earth. At such times the Moon 

 looks smaller than the Sun, and if she be at node we shall have an annular 

 eclipse — that is, there will be a ring {annulus, Lat., ring) of the Sun visible 

 around the Moon when the eclipse would otherwise have been total. 



The most simple way to protect the eyes in watching an eclipse is to use a 

 plain piece of glass smoked over a coal-oil lamp until it is sufficiently dark to 

 obscure the glare of the Sun. 



