322 Researches on Solar Physics. 
check to show whether it is free from errors of computation. 
This may be secured by deriving from it the mean for any one 
of the mean months. When the constants in the Albany equa- 
tion are transferred to the general expression for the monthly 
mean, and « and @ take the values appropriate for the third 
mean month for instance, the result is m="0975; the agreement 
of this with the daily mean for the third mean month as previ- 
ously found, is evidence that the equation of the curve has been 
computed correctly. 
January 11th, 1867, 
Art. XXXVI.—Researches on Solar Physics; by WARREN DE 
La Rug, Esq., Pres. R.A.S., BALFouR Stewart, Esq., Super 
intendent of the Kew Observatory, and Benysamin LoEwy, 
Esq., Observer and Computer to the Kew Observatory. 
Second Series (in continuation of First Series).* Area-measurement of 
the Sun-spots observed by Carrington during the seven years from 
1854-1860 inclusive, and deduction therefrom. 
34. In our first paper (Art. 13) we stated that Mr. Carrington 
had very kindly placed at our disposal all his original drawings 
of sun-spots. Our first step was to arrive at some estimate of the 
accuracy of these sketches, and we requested Dr. von Bose, who 
assisted Mr. Carrington in the greater ‘part of his observations, 
to give us a short outline of the method employed in obtaining 
them. 
From his account, it would appear that the sun’s disk was 
Wi is itherto employed, namely, the 
mere statement of the number of sun-spots occurring at any pe 
* From a memoir printed for private circulation; tables and plates, and many 
paragraphs omitted. For First Series, see p. 179. : 
