Hed&ra fielix Pe-h StK^ ZOCk. 



A,B anoLC CctfKea for fst iie^Xifi^ 



A:B-and.a - ,.. ^nd. - 



Sd. and. Cd. — Curves afitr exposure 



Mi U-dorofoy-m. i^apour. 



\5 to 25 30 35 40 45 50 

 Terrxpe'ra.tur'e, 

 Fig. 3. 



15 20 as 30 i5 40 45 50 

 'Vempevatzwes' in degrees C. 



Fig. i. 



