112 UNIVERSITY OF MISSOURI BULLETIN 



tion, you would naturally assume that you yourself were 

 really moving in the opposite direction. So, by observing the 

 velocities of a great number of stars we conclude that the 

 sun, together with the whole solar system, is moving toward 

 a certain point in the constellation Hercules with a speed of 

 about fifteen miles per second. 



The necessity of accumulating large masses of statistical 

 information has resulted in the inauguration of a number of 

 great cooperative enterprises, international in character, in 

 which astronomers all over the world take part. One of these 

 enterprises is for the purpose of studying what is called varia- 

 tion of latitude. It was found some time ago that certain 

 peculiar changes in the apparent position of the stars as a 

 whole indicate that the axis about which the earth rotates 

 is not fixed in the earth, but is moving slightly, so that the 

 earth wobbles, as it were, while rotating. The cause of this 

 is not fully known, but in order to study it more carefully 

 a number of observatories have been built in Europe, Asia, 

 and North America for the purpose of amassing observations 

 taken for this study alone. 



Another gigantic scheme is the accurate determination of 

 the positions of all the stars, from the brightest down to those 

 of the ninth magnitude, about 150,000 in all. Still another is 

 the making of photographic maps of the whole sky. The 

 results of these two pieces of work alone will prove of 

 immense value for many years in solving a number of prob- 

 lems now before us and many more that have not yet arisen. 



SOME PRESENT PROBLEMS 



Cosmogony. Of all astronomical problems, the greatest 

 and hardest is to explain how the solar system came to be 

 what it is, and what will be its final condition. The first serious 

 attempt at a solution was made by Laplace, following a sug- 

 gestion of the philosopher Kant. His theory is that the whole 



