Mar. 28, 1872] 



NATURE 



425 



and sometimes a shorter time to go from one configuration 

 to another. Thus, for instance, we have 



Mercury = earth + 0° on March 24, 1854 ; 



Mercury = earth -j- 90° on May 6, 1854 ; 

 and Mercury = earth +180° on May 29, 1854. 

 We should therefore take the observations between April 



15, 1854, and May 18, 1854, as representing the behaviour 

 of sun-spots due to a position of Mercury 90° before the 

 earth, and so on for other cases. The following table has 

 been constructed on this principle, and it may be regarded 

 as exhibiting for Mercury precisely what the second table 

 exhibited for Venus, 



Table III. 



The following is a table constructed on a precisely similar principle with reference to the planet Jupiter ; 



Table IV. 



9. If we now examine the two tables for the planets 

 Venus and Mercury, we shall find in them indications of 

 a behaviour of sun-spots appearing to have reference to 

 the positions of these planets, and which seems to be of 

 the same nature for both. This behaviour may be 

 characterised as follows : — the average size of a spot 

 would appear to attain its maximum on that side of the 

 sun which is turned away from Venus or from Mercur>', 

 and to have its minimum in the neighbourhood of Venus 

 or of Mercury. 



— 10. The apparent behaviour is so decided with regard 

 to Venus, that the whole body of observations will bear 

 to be split up into two parts, namely, Carrington's series 

 and the Kcw series, in each of which it is distinctly mani- 

 fest. The following treatment will serve to render this 

 effect more visible to the eye. 



In Table II., column (A) (Venus = earth +0°), we have 

 ten final numbers denoting the behaviour of a spot of 

 average area = 1,000 at ten central longitudes as follows : 



+ 54 + 42 + 23 - 4 — 3° — 61 — 49 — 25 + I + 49- 



Let us take the mean of the first and second of these, 

 the mean of the second and third, and so on, and we get 

 the following nine numbers : — 



+ 48 + 32 + 10 — 17 — 45 — 55 — 37 — 12 + 25. 



Performing the same operation once more, we obtain 

 the following eight numbers, corresponding to the eight 

 central longitudes : — 



+ 40 + 21 — 3 — 31 — so — 46 — 25 + 7. 



In Table V. we have exhibited the results obtained by 

 this process. 



11. If we now refer to the table of Jupiter, we find 

 that we cannot detect the same kind of behaviour that 

 we did in the case of Venus and Mercury. We cannot 

 say that such a behaviour does not exist with reference to 

 this planet ; but, if it does, it is to such an extei.; that 

 the observations at our disposal have not enabled us to 

 detect it. 



12. The following evidence from a different point of 

 view goes to confirm the results we have now obtained. 



