296 FROM NEBULA TO NEBULA 



longest axis of the given cluster, and then angling for the 

 line of the prime resultant that best fits the situation. 

 In this connection it will be illuminating to compare this 

 passage from Professor Proctor 's book, already referred 

 to (Our Place Among Infinities, pp. 201-202) : 



Father Secchi of Rome speaks thus of the distribution of 

 stars within a certain very bright portion of the Milky Way in 

 the constellation Sagittarius, as revealed by the powers of the 

 fine refracting telescope of the Roman Observatory: "There 

 are large stars and lucid clusters; then a layer of smaller stars 

 certainly below the twelfth magnitude; then a nebulous stratum 

 with occasional openings." But what startled him and all to 

 whom he showed it, was the regular disposition of the stars in 

 figures so geometrical that it is impossible to regard them as ac- 

 cidental. "They are for the most part like the arcs of a spiral', 

 one can count as many as ten or twelve stars of the ninth and 

 tenth magnitude following each other on the same curve like 

 the beads on a rosary; sometimes they seem to diverge from a 

 common center, and, strangely enough, it usually happens that 

 either at the center of the rays, or at the beginning of the branch 

 of a curve, there is a larger star of a red colour. It is impossible 

 to regard such an arrangement of the stars as accidental." 



That scholastic astronomy, notwithstanding its 

 wealth of detailed knowledge, remains primitively ignor- 

 ant of the general principles governing the movements of 

 stars, as well as of the structure and internal activities 

 of the individual stars, and that some radical reform in 

 astronomical theory is imperatively called for, will ap- 

 pear from the subjoined quotations. The first of these 

 is taken from Doctor Campbell's book (p. 216) : 



It is not easy to explain why the velocities of stars should 

 increase with their effective ages, for we are accustomed to think 

 of all matter as equally old gravitationally. Why should not the 

 materials composing a nebula or a Class B star have been acted 

 upon by gravitational forces as long and as effectively as the ma- 

 terials in the Class M stars? Are stellar materials in the ante- 

 stellar state subject to Newton's law of gravitation ? Does gravi- 

 tation become effective only after the processes of combination 

 are well under way? Is it possible that the gaseous matter com- 

 posing a nebula is acted upon as effectively by radiation pressure 

 as by gravitational attraction? The observed fact of the de- 

 pendence of stellar velocity upon the spectral class is so new 

 that these comments and questions make no pretensions to the 



