142 



MR. T. MACKERETH ON SOLAR RADIATION 



Solar Radiation (continued). 



Year 



October. 



November. 



December. 





Max. 



bk.bulb 



in sun. 



Max. in 



shade. 



Diflf. 



Max. 

 bk. bulb 

 in sun. 



Max. in 

 shade. 



Diff. 



Max. 

 bk. bulb 

 in sun. 



Max. in 



shade. 



Diff. 



1856 



1857 

 1858 



1859 

 i860 



1861 



1862 



1863 



1864 



1865 



1866 





 66-3 

 66-9 

 63-8 

 66-1 

 64-1 

 64-8 

 6i*9 

 62*0 

 617 

 62"4 

 62*5 







59*4 

 59-8 

 55-0 



56-5 

 55-4 

 6o-6 

 56-5 



559 



57-0 



586 

 58-1 





 6-9 



7"i 

 8-8 



9-6 



87 

 4-2 



5*4 

 61 



4*7 

 3-8 

 4 '4 







47*6 



56-5 

 51-8 



51-5 

 49-0 



47-2 



44"9 

 52-3 

 49-1 

 517 

 56-4 





 457 

 5o"i 

 466 

 469 

 45*3 

 45*9 

 437 

 507 

 48-2 

 50-5 

 49*5 







1-9 



6-4 



5 "2 

 4-6 



37 

 13 



I "2 



1-6 

 0-9 



1*2 



6-9 





 45 '4 

 57-5 

 50*2 

 42'6 

 40-8 

 44-0 

 48-2 

 48-6 

 41-9 

 47-8 

 52-8 





 44-8 



50-8 



45*3 

 39-8 



39-5 

 44-8 



48-0 



48-3 



43'2 

 47-4 

 47'5 





 0-6 



67 



4*9 

 2-8 



i"3 



-0-8 



0'2 

 0-3 



1-3 



0-4 



5-3 



Means 



63-86 



57-47 



6-39 



5073 



47-55 



3-.8 



47-26 



45-40 



1-86 



Monthly values. 



Max. in sun. Max. in shade. 



Diff. 



January 45-77 43-32 2-45 



February 49*90 45*43 4'47 



March STS"^ 48*41 911 



April 69-84 56*67 I3"i7 



May 77*37 62-53 14-84 



June 83-63 68-88 14-75 



July 84-76 69-45 15-31 



August 81-26 68-34 12-92 



September ... 75'ii 64*26 10-85 



October 63-86 57*47 6-39 



November ... 50*73 47*55 3'i8 



December ... 47-26 45'40 i"86 



VII. A Comparison of Solar Radiation on the Grass and 

 at Six Feet from the Ground. By Thomas Mackereth^ 

 F.R.A.S., F.M.S. 



Eead November 26th, 1867. 



As the Corporation of the Borough of Salford has re- 

 cently erected a structure in front of the Town Hall for 



