ASTRONOMY AND METEOROLOGY. 325 



knowledge we have now attained that arrested motion is represented 

 by equivalent heat. Telescopic observations will probably add new 

 facts to guide our judgment on this subject, and, taken in connection 

 with observations on terrestrial magnetism, may enlarge and correct 

 our views respecting the nature of heat, light and electricity. Much 

 as we have yet to learn respecting these agencies, we know sufficient 

 to infer that they cannot be transmitted from the sun to the earth ex- 

 cept by communication from particle to particle of intervening matter. 

 Not that I speak of particles in the sense of the atomist. Whatever 

 our views may be of the nature of particles, we must conceive them as 

 centres invested with surrounding forces. We have no evidence, 

 either from our senses or otherwise, of these centres being occupied by 

 solid cores of indivisible incompressible matter essentially distinct from 

 force. Dr. Young has shown that even in so dense a body as water, 

 these nuclei, if they exist at all, must be so small in relation to the in- 

 tervening spaces, that a hundred men distributed at equal distances 

 over the whole surface of England would represent their relative mag- 

 nitude and distance. What then must be these relative dimensions in 

 highly rarefied matter ? But why encumber our conceptions of ma- 

 terial forces by this unnecessary imagining of a central molecule ? If 

 we retain the forces and reject the molecule, we shall still have every 

 property we can recognize in matter by the use of our senses or by the 

 aid of our reason. Viewed in this light, matter is not merely a thing 

 subject to force, but is itself composed and constituted offeree." 



Connection between Sun-spots and Planetary Configurations. At 

 the British Association, 1863, Mr. B. Stewart stated, that in the course 

 of some recent investigations, as to whether there was any determinable 

 connection between sun-spots and planetary configurations, he was led 

 to observe the changes with regard to size which take place in sun- 

 spots, from a remark by Mr. Beckley, of Kew Observatory, that, dur- 

 ing a certain period, he did not observe any spots break out on the 

 visible disk of our luminary. Besides about six months' records of these 

 phenomena, made by means of the Kew photoheliograph at the Kew 

 Observatory, the author has had the opportunity of investigating a 

 year's records made by the same instrument at Mr. De La Rue's private 

 Observatory at Cranfbrd. All of these are collodion negatives, and, 

 besides embracing a few months in the end of 1859, they give an al- 

 most continuous record of the state of the sun's disk between February, 

 1862, and the present date. There is little difficulty in finding from 

 these, by means of a comparison of two or three consecutive pictures, 

 approximately, at what portion of the sun's disk any spot ceases to in- 

 crease and begins to wane, or, on the other hand, breaks out into a 

 visible appearance. Now it appears to be a law nearly universal, that 

 if we divide the disk of the sun roughly into longitude by vertical di- 

 ameters, and if there be a number of spots on the surface of the sun, 

 these will all behave in the same manner as they cross the same longi- 

 tude ; that is to say, if one spot decreases, another will decrease* also, 

 and so on. This law can, of course, be only approximately ascertained 

 by means of a preliminary examination of this nature ; but the impres- 

 sion produced upon the author is very strong, that if one spot decreases 

 before coming to the central line, another does the same ; if, on the 

 other hand, one spot breaks out on the right half and increases up to 



28 



