90 THE SUN, 



become familiar when we contemplate the sun. In what 

 has been said, it will be perceived that I have been more 

 anxious to dwell upon facts than theories, and rather to 

 supply the imaginations of my audience with materials for 

 forming a just conception of the stupendous magnificence 

 of this member of God's creation, than to puzzle them 

 with physical and mathematical reasonings and argu- 

 ments. 



Note on 12. The effect of any supposed small loss of time in 

 the transmission of the sun's attractive force on the earth across the in- 

 tervening space, may be very easily made intelligible without going 

 through any abstruse calculation. The pull exerted on the earth 

 would be delivered there, not in the direction of the line joining the 

 sun and eartli at the instant of its arrival, but of that which did]o\\\ 

 them when it left the sun. Its action on the earth would therefore 

 be oblique to their actual line of junction, or to what is called the 

 radius vector of the orbit tending, not towards the sun, but towards 

 a point somevvhat in advance of it {i.e., lying from it in the direc- 

 tion in space of the region towards which the earth is moving). 

 This force then being resolved in radial and tangential directions 

 would produce, in the former, a force directed to the sun differing 

 by a mere infinitesimal from its direct gravity and in the latter, one 

 always accelerating the eaj-th in its orbit, and which, however minute, 

 must of necessity result in a continually progressive increase of the 

 major axis, and therefore of the length of the year. Supposing the 

 transmission of gravity to be performed with the speed only of light 

 - the inclination of the line of pull to the radius vector would be 

 20" "25 (the exact value of the coefficient of aberration), and the 

 accelerating tangential force thence resulting would amount to 

 i-ioi8Sth part of the sun's direct attraction, a force whose effects 

 would become evident in a very few years to say nothing of the 

 centuries elapsed since the first determination of the length of the 

 year. 



