322 Royal Astronomical Society, 



stellar orbit, have passed, and may yet have to pass, through regions 

 of space, in which the light-yielding element may either abound or 

 be deficient, and so cause him to beam forth with increased splen- 

 dour, or fade in brilliancy, just in proportion to the richness or 

 poverty of this supposed light-yielding element as may occur in- 

 those regions of space through which our sun, in common with 

 every stellar orb, has passed, is now passing, or is destined to pass, 

 in following up their mighty orbits. 



" Once admit that this light-yielding element resides in space, 

 and that it is not equally diffused, we may then catch a glimpse of 

 the cause of the variable and transitory brightness of stars, and 

 more especially of those which have been known to beam forth with 

 such extraordinary splendour, and have again so mysteriously faded 

 away; many instances of which abound in historical record. 



*' Finally, in reference to such a state of change having come 

 over our sun, as indicated by the existence of a glacial period, as is 

 now placed beyond doubt by geological research, it appears to me 

 no very wild stretch of analogy to suppose that in such former pe- 

 riods of the earth's history our sun may have passed through portions 

 of his stellar orbit in which the light-yielding element was deficient, 

 and in which case his brilliancy would have suffered the while, and 

 an arctic climate in consequence spread from the poles towards the 

 equator, and leave the record of such a condition in glacial hand- 

 writing on the everlasting walls of our mountain ravines, of which 

 there is such abundant and unquestionable evidence. As before 

 said, it is the existence of such facts as we have in stars of transi- 

 tory brightness, and the above-named evidence of an arctic climate 

 existing in what are now genial climates, that renders some ade- 

 quate cause to be looked for. I have accordingly hazarded the pre- 

 ceding remarks as suggestive of a cause, in the hope that the sub- 

 ject may receive that attention which its deep interest entitles it to 

 obtain. 



" This view of the source of light, as respects the existence of the 

 luciferous element throughout space, accords with the Mosaic ac- 

 count of creation, insofar as that light is described as having been 

 created in the first instance before the sun was called forth." 



. Note by the Astronomer Royal. 



" In an oral address to the Society, on 1849, December 14, an 

 abstract of which is printed in the Monthly Notices, vol. x. No. 2, 

 in describing the method of recording transits by the agency of a 

 galvanic current, I ascribed certain steps of the invention to Dr. 

 Locke and Professor Mitchell. I have lately been informed that 

 the invention was also shared by Mr. Bond, Mr. Walker, and per- 

 haps by other persons. I am desirous of explaining to the Society 

 that the history, such as I gave it at that time, was founded upon 

 the printed papers which had then reached me, and upon my cor- 

 respondence with American friends ; both necessarily imperfect 

 sources of information ; and that I had no wish to assert the claims 

 of Messrs. Locke and Mitchell further than as they seemed to be 

 implied in those documents, nor to express any opinion on the claims 



