332 Capt. Abney and Col. Festing. [June 21, 



Annexed are tables showing the ordinates of the different points of 

 the spectra as determined by the thermopile. 



Curves. (See Diagram I.) 



Scale No. 



I. 



II. 



III. 



IV. 



V. 



VI. 



VII. 



Vlll. 





-10 



•5 



•4 



•4 



•4 







•5 



•5 









— 8 



1 -3 



•9 



•9 



•9 







1 -3 



1 -3 









- 6 



2 5 



1 3 



1 -3 



1 -3 







2 -5 



2-5 









— 4 



4*4 



2 -5 



2 *5 



2 3 



•2 



4*4 



4*1 



•3 





- 2 



5*9 



4-5 



4-3 



4-1 



1-2 



5-5 



5 -0 



2 -0 









11-0 



7-5 



7 '3 



6 *8 



3-2 



10 -5 



9 -5 



4'7 



This point is 



i 



12 -3 



8 -7 



8-7 



8'5 



4-0 



12 -3 



12 -0 



5-7 



D. 



1 



13 -7 



10 



9 '2 



8 -8 



3-7 



13 -0 



12-3 



5 3 







15*1 



11 3 



10 7 



10 -o 



5-0 



14-0 



13-3 



— 





2 



16-8 



12 -8 



12 *2 



11*6 



6-7 



16*0 



15-0 



— 





3 



21 -5 



16-0 



15 9 



15 -0 



10-3 



21 -4 



20'0 



— 





n 



23 -0 



16 -7 



16*7 



16 -0 



10 -7 



23 -0 



22-5 



15-3 





3| 



24-2 



17 '5 



17*5 



16-7 



8-5 



24 -2 



23-0 



— 





4 



27-5 



19-3 



18 *5 



17 -0 



2 3 



26 -0 



24'0 



3*5 



This point is 



4i 



31 '5 



21 -1 



21 '0 



19 *2 



1 -8 



31 -5 



28 -0 



— 



A. 



5 



35 -0 



22 '8 



22 '8 



20*6 



1 4 



35 "0 



32 -2 



2*0 





5* 



38 '2 



24 'Q 



23 *0 



21 -0 



— 



36 *0 



33 -0 



— 





5$ 



40 -0 



25 '4 



24 '7 



22-0 



— 



38*7 



34-5 



— 





6 



41 '2 



26 2 



24 -3 



20-0 







38 -0 



27-0 









6| 



42 -3 



27 -0 



23 "0 



14-0 



w. 



— 



— 



GO 



►a 





6i 



43 '3 



27 -7 



21 - 5 



5 -3 



^5 



CD 

 O 



33 -7 



8-5 



CD 

 O 





6| 



44 '5 



28 -4 



24 '0 



6 -0 





— 



— 









45 *3 



29 -3 



26 "0 



9-0 



& 



— 



— 



s 





7i 



46*5 



30 -0 



26 -3 



10-0 





40-2 



15 5 



CD 





7i 



45 -7 



29-4 



25 -0 



9-7 



2 

 & 



— 



— 







8 



43 -2 



27 -6 



20*5 



1-5 





32 2 



— 





The minimum 



8i 



— 



— 



18 *5 



•5 





28 -0 



•8 





probably 



8| 



40 -0 



25 -8 



18 -5 



•5 





— 



— 





lies a little 



8f 



— 



— 



19 -0 



•7 





— 



— 





closer to 8 



9 



37 -3 



24-0 



16*0 



•5 





— 



— 





than 8£. 



9| 



34-3 



21-4 



6-0 









9-7 











10 



31 -3 



18-5 



•7 









1-3 



'"d 







1 Ai 

 lUa 





1 K -fi 



io u 



JL O 



w. 



CD 

 O 







CD 

 O 







11 



24-0 



11 -6 



3-0 





5-3 



el- 







HI 







16 



ei> 







t 







12 



15-5 



6-8 



1-0 



pi 



i 



CD 







CD 







12| 























13 



9-0 



4-0 



•4 



fcJ 







Xli 







131 







1-5 



GO 





2-8 









14 



3-7 



1-8 



11 















15 



1 -8 



•8 





















18 

























A reference to the diagram will show that the thermograms of the 

 water spectra have absolute coincidence with the absorptions shown 

 in the photographs. The thermogram is, however, more delicate in 

 some respects ; as for instance, in the dip in the carves commencing 

 at \ in the scale. This is a water-band which is only shown photo- 

 graphically and markedly with 4 feet of water, whilst with but 



