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SCIENCE 



[N. S. Vol. XXXIII. No. 838 



But there are certain differences which call 

 for special notice. The minima of the peri- 

 helia and eccentricity which occurs in the 

 group 7 with the first 300 asteroids occurs in 



should, of course, be diminished by one 

 eleventh of its height, for strict comparison 

 with the first chart, on account of the total 

 numbers of planets used; but this does not 



Fig. 5 



the group 6 with the last 330 asteroids ; the 

 displacement does not appear to be acci- 

 dental. But the most remarkable differ- 

 ence is the greater range between maxi- 

 mum and minimum with the later discov- 

 ered and presumably smaller bodies with 

 the earlier ones; this difference is observ- 

 able in both the perihelia and eccentricity 

 curves. Each ordinate of the curve which 

 represents the perihelia in the second chart 



materially affect the observation. The 

 range is greater by nearly 50 per cent, for 

 the perihelia and by nearly 80 per cent, for 

 the eccentricities. Is this a relic of the 

 initial conditions or the effect of some force 

 other than gravitation, for example, light 

 pressure or the impact of material particles 

 entering or leaving the solar system, in 

 which the mass of the asteroids affected 

 will play some part 1 There is here a wide 



