42 



WRITINGS OF JOSEPH HENRY. 



[1855- 



ferent northern latitudes, is greater than that which fells 

 upon the equator during the same time. This is exhibited 

 in the following table, from the paper of L. W. Meech on the 

 sun's intensity, in the 9th volume of the Smithsonian Con- 

 tributions, [page 18] : 



The sun's diurnal intensity at every ten degrees of latitude in the northern 



hemisphere. 



1853. 



Lat. 

 0°. 



Lat. 

 10°. 



Lat. 

 20°. 



Lat. 

 30°. 



Lat. 

 40°. 



Lat. 

 50°. 



Lat. 

 60°. 



Lat. 

 70°. 



Lat. 

 80°. 



Lat. 

 90°. 



Jan. 1 



Jan. 16 



Jan. 31 



Feb. 15 



Mar. 2 



Mar. 17 



April 1_. 



April 16_. 

 May 1-, 

 May 16.. 



May 31-. 



June 15-. 



July 1- 



July 16.. 



July 31.. 



Aug. 15_. 



Aug. 30. 

 Sept. 14. 



Sept. 29 



Oct. 14 



Oct. 29 



Nov. 13 



Nov. 28 



Dec. 13 



77-1 

 78-1 

 79-6 

 81-0 

 81-6 

 82-0 



80-8 



79 

 76-9 

 74-7 



73-0 

 72-0 

 720 

 730 



74-7 

 76-7 



78-5 

 79-8 



80-5 

 80-7 

 79-9 

 78-8 

 77-5 

 76-9 



67-2 

 68-9 

 71-7 

 74-7 

 78-0 

 80-2 



81-4 



81-7 

 81-5 

 80-8 



80-1 

 79-6 

 79-5 

 79-8 



80-4 

 80-8 



80-7 

 79-8 



78-4 

 76-4 

 73-5 

 70-7 

 68-3 

 66-9 



65-8 

 58-2 

 61-9 

 66-6 

 71-3 

 76-0 



79-5 



82-0 

 83-7 

 84-7 



85-1 

 85-2 

 85 



84-7 



83-9 

 82-7 



80-6 

 77-5 



73-8 

 69-7 

 650 

 60-8 

 57-3 

 55-4 



42-8 

 45-8 

 49-7 

 55-6 

 62-9 

 69-6 



75-3 



79-5 

 83-6 

 86-7 



87-8 

 88-4 

 88-5 

 87-5 



85-1 

 82-4 



77-7 

 72-6 



67-0 

 610 

 54-6 

 49-8 

 45-3 

 430 



30-1 

 32-7 

 38-6 



16-5 

 19-3 

 25-0 



51 

 7-2 

 11-9 

 19-0 

 27-9 

 37-1 



49-9 



61-1 

 70-9 

 79-7 



85-7 

 88-8 

 88-4 

 84-1 



77-3 

 68-2 



57-3 

 46-9 



36-2 

 25-7 

 17-5 

 11-0 

 0-8 

 4-9 



1-4 



6-4 



14-5 



25-5 



380 



51-4 



64-6 

 76-8 



8G-8 

 91-7 

 90-8 

 84-3 



73-4 

 60-9 



47-7 

 34-5 



22-5 



12-6 



5-2 



0-9 



21 

 11-6 



25-6 



440 

 643 

 80-3 



91-0 

 96-1 

 95-1 



88-3 



70-2 

 59-2 



38-8 

 21-9 



9-0 

 1-0 



20-5 



44-6 

 65-3 

 81-5 



92-4 

 97-6 

 96-6 

 89-7 



77-4 

 60-1 



38-9 

 14-7 



On the fifteenth of June the sun is more than 23 degrees 

 north of the equator, and therefore it might be readily in- 

 ferred that the intensity of heat should be greater at this 

 latitude than at the equator ; but that it should continue to 

 increase beyond this even to the pole, as indicated b}'' the 

 table, may not at first sight seem so clear. It will how- 

 ever be understood, when it is recollected that the table in- 

 dicates the amount of heat received during the whole day ; 



