262 Mr. J. Ennis on the Physical and Mathematical 





Deflections. 









Angle between 

 principal sec- 

 tions = 0. 









d 

 cos 2 9' 



8' 



(calculated). 



s v 



8 2 . 



Mean 

 8. 



o 







32-25 



315 



31-9 



31-9 



311 



15 



2975 



2925 



29-5 



31 6 



290 



30 



2275 



235 



231 



30-8 



233 



45 



1475 



14-75 



14-75 



29-5 



15-5 



60 



775 



7-75 



7-75 



310 



7-8 



75 



225 



20 



21 



317 



21 



90 



0-5 



025 



0-4 





00 









Mean ... 



31-1 





The numbers in the last column of the Table are calculated 

 by the formula 5' = 31*1 cos 2 6. It will be seen that the ob- 

 served mean values (S) never differ from the corresponding 

 calculated values (8 X ) by a whole division of the scale, which 

 represents about as high a degree of accuracy as can be ex- 

 pected from the method of observation employed, it being 

 impossible to read with certainty to any thing less than half 

 a division : where quarter divisions occur in the Table, they 

 result from taking the means of positive and negative deflec- 

 tions. 



XXXV. Physical and Mathematical Principles of the Nebular 

 Theory. By Jacob Ennis, A.M.* 



THE chief objections against the derivation of the stars 

 from a former gaseous diffusion of matter have been these 

 two : — first, that no cause can be discovered for the beginning 

 of rotation in the primitive gaseous condition ; and secondly, 

 that this rotation, even if begun, could not become rapid 

 enough to produce a centrifugal equal to the centripetal force, 

 and thus to separate equatorial rings which may break and 

 condense into revolving stars. Both these objections I will 

 now remove. 



First. The force of gravity, by its interaction between nebu- 

 lous masses, 7nust necessarily begin rotation. — Sir Isaac New- 

 ton says that "if matter were evenly diffused through a^ finite 

 space and endowed with innate gravity, it would fall down in 

 the middle of that space and form one great spherical mass ; 

 but if matter were diffused through infinite space, some of it 

 would collect into one mass and some into another, so as to form 

 an infinite number of great masses. In this manner the sun 

 and stars might be formed, if the matter were of a lucid nature." 

 This is sound reason, an unavoidable conclusion. Therefore, 

 * Communicated by the Author. 



