Joseph Baxendell, F.R.S. 41 



dimensions of the ring and its period of revolution round the 

 sun will also vary, their maximum and minimum values 

 occurring respectively at the time of maximum and mini- 

 mum solar spot frequency. The matter of the supposed 

 ring may be diamagnetic and, being much nearer to the 

 sun than any of the known planets, of much greater bulk 

 and lightness, and being subjected to a much higher tempe- 

 rature it will be very sensibly affected by the changes which 

 take place in the magnetic condition of the sun, and 

 when interposed between the sun and the earth it 

 may act not only by reflecting and absorbing a por- 

 tion of the heat and light which would otherwise 

 reach the earth, but also by altering the direction of the 

 lines of magnetic force ; we may also fairly conclude that 

 the action of the supposed ring of nebulous matter is 

 principally of a magnetic, and but slightly of a thermal 

 character. From the max. and min. values of the temperature 

 period the greatest and least values of the sidereal period of 

 revolution of the ring will be 29*12, and 22*08 days respec- 

 tively. From these numbers we find that the greatest 

 distance of the ring from the sun is 0*185, the radius of the 

 earth's orbit being taken as unity, the least distance 0*154, 

 and the mean 0*169. The greatest attractive force of the 

 sun on the ring being taken as unity the least will be 0*619 — 

 the difference, he thinks, may be taken as a measure of the 

 force concerned in the production of the solar spots. He 

 then refers to Leverrier's observations on the motion of 

 Mercury, leading to the view that there was a disturbing 

 body circulating round the sun within the planet's orbit, 

 and that the mass consisted of a ring of small bodies ; the 

 mean distance which Leverrier regarded as the most prob- 

 able is precisely that which the author has found for the 

 ring of nebulous matter whose existence he has assumed. 

 "This unexpected and unlocked for agreement, between 

 results arrived at from considerations and by methods so 



