9S POPULAR SCIENCE MONTHLY. 



With the sun at such a low altitude, the atmospheric disturbances and 

 the almost complete absorption of actinic rays will preclude the possi- 

 bility of securing satisfactory observations, except perhaps as to the 

 general form of the corona. It is known that the Chilean astronomers 

 are expecting to view the phenomenon. Further plans do not seem to 

 be called for. 



The next observable eclipse is that of August 30, 1905. It is well 

 situated, and will be looked forward to with unusual interest. The 

 shadow path begins at sunrise south of Hudson's Bay, enters the 

 Atlantic Ocean a short distance north of Newfoundland, crosses north- 

 eastern Spain, northeastern Algiers and northern Tunis, passes cen- 

 trally over Assuan on the Nile, and ends at sunset in southeastern 

 Arabia. The durations on the coast of Labrador, in Spain and at 

 Assuan, are two and a half, three and three fourths and two and three 

 fifths minutes, respectively. 



It is none too soon to form plans for observing this eclipse. In 

 this connection, an account of the leading eclipse problems now press- 

 ing for solution may have interest for the general reader, and perhaps 

 some usefulness to those who will plan programs of work, though the 

 latter will prefer a more detailed article than would be justified here. 



There is probably no phenomenon of nature more beautiful and 

 impressive than a total eclipse of the sun. Every such event is of great 

 human interest. Even the uncivilized tribes of the earth realize, 

 crudely, the force of the scientific fact that the sun is the origin of the 

 light, heat and other forms of energy which make life on this planet 

 possible. 



The absorbing interest taken in eclipses by astronomers is on a 

 broader basis. Our sun is one of the ordinary stars. In size it is per- 

 haps only an average star ; or it may even be below the average. It is 

 the only star near enough to us to show a disk. All other stars are 

 as mathematical points, even when our greatest telescopes magnify 

 them 3,000-fold. The point-image of a distant star includes all its 

 details, and it must be studied as a whole, whereas the sun can be 

 studied in geometrical detail. Our sun is likewise the only star bright 

 enough to supply metrical standards demanded in the study of other 

 stars. It is not too much to say that our physical knowledge of the 

 stars would to-day be practically a blank if we had been unable to 

 approach them through the study of our sun. If we would understand 

 the other stars, we must first make a complete study of our own star. 

 Several of the most interesting portions of our sun are invisible, except 

 at times of solar eclipse. Our knowledge of the sun will be incomplete 

 until these portions are thoroughly understood; and this is the reason 

 why eclipse expeditions are despatched, at great expense of time and 

 money, to occupy stations within the narrow shadow belts. 



