Mr. J. J. Waterston on Solar Radiation. 



511 



ing these observations with different surfaces. One result is 

 interesting* as showing the perfect reciprocity of the radiation, 

 viz. a gilt bulb radiating against a blackened metallic surface 

 loses heat at the same rate as a blackened bulb against a bright 

 metallic surface, the rate being slower than when both are 

 blackened. 



Observations on Solar Radiation, 





Apparent time. 

 Latitude, 

 55° 58' N. 

 Longitude, 



Oh. 12m. 44s. W. 



O 



la 

 n 



2* 



gss 



"43 o 3 



O u 3 



<u a a 



If* 



(. (3 . 



O-a s 

 <u g o 



.3 § £ 



■a . 



- -n 



■a*g . 



go a 



«S m J? 



a s o 



oi| 



O hi 



o 



CO 



Remarks. 















1 ; 



App. 











To. 



ra. 



F* 



r v . 



rv 



alt. 







1861. 



h m 



o 



o 



o 









o / 







July 28. 



4 25 p.m. 



17-5 



20-6 



+ 7*4 



28-0 



•0357 



28 49 



2-075 







4 36 



16-5 



19-5 



6-8 



26-3 



•0380 



27 19 



2-183 







4 56 



15-5 



18-3 



6-2 



24-5 



•0408 



24 30 



2-411 







5 26 



14-0 



16-5 



5-2 



21-7 



•0461 



20 19 



2-880 







6 18 



13-2 



15-5 



4-7 



20-2 



•0495 



13 11 



4*385 





Aug. 6. 



8 7 A.M. 



16-2 



19-1 



6-6 



25-7 



'0389 



31 17 



1-926 







9 8 



18-0 



21-2 



7-7 



28-9 



•0346 



42 21 



1-484 







9 32 



18-3 



21*6 



8-0 



29*6 



•0338 



45 12 



1-409 





13. 



7 27 p.m. 



2-2 



2-6 



03 



2-9 



•3448 



53 





Sunset 



16. 



5 16 A.M. 



4-4 



5-2 



0-8 



60 



•1667 



5 29 



10-465 



Sun rises per- 





9 39 



14-6 



17*2 



5-6 



22-8 



•0439 



39 51 



1-561 



fectly clear of 





11 3 



15-0 177 



5-8 



23-5 



•0425 



46 20 



1-382 



clouds. 



20. 



6 21 16 p.m. 



6-6 



7-7 



+ 1-4 



9-1 



•1099 



7 21 



7-817 



" 







6 23 16 



6-5 



7-6 



1-4 



9-0 



•1111 



7 4 



8-128 









6 24 31 



6-4 



75 



1-4 



8-9 



•1124 



6 55 



8-304 









6 26 16 



6-1 



7-2 



1-3 



8-5 



•1177 



6 41 



8-592 





Consecutive 





6 27 16 



6-0 



7-1 



1-2 



8-3 



•1205 



6 33 



8-767 



y series not 





6 28 36 



6-1 



7-2 



1-3 



8-5 



•1177 



6 22 



9-018 



equalized. 





6 31 



5-7 I 6-7 



1-1 



7-8 



•1282 



6 2 



9-514 







6 37 16 



4-8 



5-7 



0-8 



6-5 



•1538 



5 12 



11-034 



J 





6 39 



4-7 



5-6 



0-8 



6-4 



•1562 



4 59 



11-512 



21. 



7 20 a.m. 



9-8 



11-6 



2-9 



14-5 



•0690 



19 



3-071 



1 





7 40 



10-7 



12-6 



3-3 



15-9 



•0629 



21 45 



2-698 



Consecutive 





8 



11-6 



13-7 



3-8 



175 



•0571 



24 29 



2-413 



j series gra- 





8 20 



12-3 



14-5 



4-2 



18-7 



•0535 



27 9 



2-191 



phically 

 | projected 





8 40 



13-0 



,15-3 



4-6 



19-9 



•0502 



29 45 



2-015 





9 



13-5 



45-9 



4-9 



20-8 



•0481 



32 14 



1-874 



and equal- 

 ized. 





9 20 



13-8 



16-2 



5-0 



21-2 



•0472 



34 37 



1-760 





9 40 



14-1 



16-6 



5-3 



21-9 



•0457 



36 50 



1-6681 j 



[The observations taken on seven other days between July 

 28 and August 28 are here omitted.] 



