﻿Royal Society '. 537 



Having arrived at the conclusion that Saturn's rings originated 

 from an encounter of the planet with a group of meteors, the author 

 seeks for information relative to the period of attachment. He con- 

 ceives that the Saturnian meteors, and those now composing the 

 zodiacal light, entered the solar system together, at a period con- 

 siderably anterior to that of the sun's first luminosity, but not much 

 anterior to the earth's early fluid state. " Geologists," he says, 

 " have given the duration of the period throughout which the earth 

 has borne living species, variously from one to nine millions of years. 

 We may therefore conclude that the formation of Saturn's meteoric 

 rings has occurred not much more recently than two millions of 

 years ago, and probably at a date not very much more remote than 

 nine millions of years. The earth's original fluid state was probably 

 owing to a meteoric storm due to the entry of the meteors into the 

 solar system." 



To the meteoric theory of Saturn's rings is appended a paper on 

 the meteoric theory of the sun, in which the author considers that 

 the source of energy from which solar heat is derived is undoubtedly 

 meteoric, and that the solar spots result from the absence of me- 

 teoric streams falling into the sun, which make themselves manifest 

 as " willow leaves," — also that the periodicity of sun-spots is accounted 

 for by a periodicity of the meteoric flights, fewer meteors falling on 

 the sun during the maximum period of spots. 



We have in the preceding paragraphs endeavoured to give a faith- 

 ful analysis of the work before us. With regard to the assumption 

 on which the author's conclusions are based, we leave it with his 

 readers to exercise their own judgment. Mr. Proctor has lately 

 broached a theory of solar eruption, in which he considers that the 

 solar coronal matter consists of meteors ejected from the sun, and 

 rushing through the photosphere with a velocity of 200 miles a second, 

 the initial velocity (generated at a point far below the photosphere) 

 being not less than 300 miles a second. Lieut. Davies speaks of 

 the probable velocity of a meteor falling into the sun from space 

 just prior to its final dissipation on the surface as ranging from 

 246 to 390 miles a second. The two theories are now before the 

 public, and will doubtless furnish material for further and closer 

 investigation. 



LXIX. Proceedings of Learned Societies. 



ROYAL SOCIETY. 

 [Continued from p. 398.] 



January 19, 1871. — General Sir Edward Sabine, K.C.B., President, 



in the Chair. 

 fPHE following communications were read : — 

 -*- " Modification of Wheat stone's Bridge to find the Resistance 

 of a Galvanometer-Coil from a single deflection of its own needle." 

 By Prof. Sir William Thomson, F.R.S. 



In any useful arrangement in which a galvanometer or electrometer 

 and a galvanic element or battery are connected, through whatever 



