66 Royal Society : — Frank] and and Lockyer on Gaseous Spectra 



the battery, the needles remained nearly stationary during several 

 seconds, and then went rapidly to about 10 : this slow decline of the 

 current during the first few seconds of cooling was probably connected 

 with the " momentary molecular change of iron wire " during cooling 

 which I have described in the preceding paper. The irregularity of 

 movement of the needles did not occur unless the wire was bright red- 

 hot, a condition which was also necessary for obtaining the molecular 

 change. 



The direction of the current induced by heating the iron wire was 

 found by experiment to be the same as that which was produced by 

 removing the magnet from the coil ; therefore the heat acted simply 

 by diminishing the magnetism, and the results were in accordance 

 with, and afford a further confirmation of, the general law, that where- 

 ever there is increasing or decreasing magnetism, there is a tendency 

 to an electric current in a conductor at right angles to it. 



February 11. — Dr. W. B. Carpenter, Vice-President, in the Chair. 



The following communication was read: — 



"Preliminary Note of Researches on Gaseous Spectra in relation 

 to the Physical Constitution of the Sun." By Edward Frankland, 

 F.R.S., and J. Norman Lockyer, F.R.A.S. 



1 . For some time past we have been engaged in a careful exami- 

 nation of the spectra of several gases and vapours uuder varying con- 

 ditions of pressure and temperature, with a view to throw light upon 

 the discoveries recently made bearing upon the physical constitution 

 of the sun. 



Although the investigations are by no means yet completed, we 

 consider it desirable to lay at once before the Royal Society several 

 broad conclusions at which we have already arrived. 



It will be recollected that one of us in a recent communication to 

 the Royal Society pointed out the following facts : — 



i. That there is a continuous envelope round the sun, and that in 

 the spectrum of this envelope (which has been named for accuracy of 

 description the " chromosphere ") the hydrogen line in the green 

 corresponding with Fraunhofer's line F takes the form of an arrow- 

 head, and widens from the upper to the lower surface of the chromo- 

 sphere. 



ii. That ordinarily in a prominence the F line is nearly of the same 

 thickness as the C line. 



hi. That sometimes in a prominence the F line is exceedingly 

 brilliant, and widens out so as to present a bulbous appearance above 

 the chromosphere. 



iv. That the F line in the chromosphere, and also the C line, extend 

 on to the spectrum of the subjacent regions and re-reverse the Fraun- 

 hofer lines. 



v. That there is a line near D visible in the spectrum of the chro- 

 mosphere to which there is no corresponding Fraunhofer line. 



vi. That are many bright lines visible in the ordinary solar spec- 

 trum near the sun's edge. 



vii. That a new line sometimes makes its appearance in the chro- 

 mosphere. 



