Temperature of Evaporation. 



411 



TABLE VII. — Daily, "Weekly, and Monthly Means of the Temperature of Evaporation, as deduced 

 from the Readings of the Wet Bulb Thermometer, in 1844. 



Civil 

 Day. 



Jan. 



Feb. 



March. 



April. 



May. 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



1 



28-8 



27-4 



36-2 



42-2 



45-8 



46-1 



49-4 



52-3 



[53-9] 



49-5 



41-8 



[37-4] 



2 



250 



30-6 



34-5 



44-6 



49-3 



[48-1] 



49-7 



51-3 



54-5 



49-0 



39-9 



36-4 



3 



32-3 



29-2 



[32-7] 



42-5 



46-3 



47-0 



50-5 



48-9 



52-7 



49-9 



[41-8] 



35-7 



4 



34-5 



[27-6] 



32-5 



38-9 



44-6 



50-2 



47-6 



[52-0] 



55-8 



45-8 



40-1 



311 



5 



450 



25-4 



28-4 



37-7 



[47-0] 



54-4 



50-2 



54-2 



56-3 



43-5 



415 



25-7 



6 



42-0 



22-7 



29-9 



37-5 



50-4 



56-8 



50-5 



53-0 



57-4 



[43-9] 



42-3 



22-0 



7 



[38-0] 



'30-3 



30-4 



[42-2] 



46-8 



55-6 



[50-7] 



52-3 



58-7 



38-2 



40-5 



23-2 



8 



36-2 



315 



33-7 



46-1 



44-6 



54-5 



50-5 



51-9 



[53-7] 



40-1 



43-2 



[27-3] 



9 



32-7 



33-9 



42-2 



50-1 



46-0 



[53-3] 



52-2 



49-8 



51-1 



46-1 



43-3 



30-4 



10 



37-5 



30-2 



[34-6] 



43-1 



45-6 



500 



531 



48-3 



48-7 



49-5 



[40-7] 



321 



11 



39-6 



[33-5] 



38-0 



40-5 



48-1 



500 



51-7 



[51-3] 



500 



47-8 



37-2 



30-2 



12 



40-7 



30-4 



31-9 



41-7 



[47-0] 



52-8 



49-8 



52-8 



47-5 



48-3 



37-9 



29-0 



13 



33-4 



34-3 



31-3 



44-4 



50-7 



54-8 



50-8 



52-4 



47-7 



[47-5] 



42-0 



28-2 



14 



[34-6] 



40-8 



331 



[43-1] 



47-4 



50-4 



[49-7] 



52-5 



51-5 



47-4 



39-7 



33-3 



15 



27-5 



40-5 



32-6 



46-9 



44-1 



48-7 



47-6 



52-9 



[49-1] 



46-2 



47-0 



[33-3] 



16 



30-8 



36-9 



30-9 



40-4 



44-7 



[50-1] 



48-8 



51-8 



54-1 



45-6 



48-2 



34-8 



17 



35-5 



38-9 



[33-3] 



44-9 



38-0 



48-5 



49-6 



50-2 



49-4 



44-4 



[46-0] 



37-2 



18 



39-2 



[33-5] 



30-3 



42-3 



36-1 



50-4 



51-0 



[51-2] 



44-2 



40-3 



47-7 



37-1 



19 



36-5 



33-7 



37-8 



47-6 



[41-3] 



48-0 



49-2 



51-5 



46-4 



36-6 



48-5 



31-8 



20 



31-4 



26-7 



34-9 



501 



41-0 



48-9 



49-1 



51-3 



44-9 



[38-4] 



45-1 



23-7 



21 



[35-2] 



24-1 



331 



[44-8] 



44-4 



54-9 



[54-2] 



49-3 



41-0 



36-7 



37-3 



28-1 



22 



35-7 



220 



40-5 



43-9 



43-7 



540 



58-4 



50-6 



[44-3] 



38-1 



31-3 



[29-7] 



23 



351 



27-5 



38-7 



44-2 



43-6 



[51-7] 



58-2 



51-9 



42-3 



34-6 



37-8 



32-6 



24 



33-6 



30-3 



[40-2] 



40-6 



44-7 



57-4 



59-5 



50-5 



45-9 



34-6 



[36-5] 



31-3 



25 



40-8 



[28-1] 



40-6 



45-3 



43-6 



48-6 



58-2 



[49-1] 



45-2 



43-2 



30-3 



30-5 



26 



38-5 



28-0 



42-2 



42-9 



[43-5] 



46-4 



57-4 



48-0 



531 



43-9 



36-5 



31-2 



27 



44-9 



27-4 



46-3 



40-4 



43-0 



46-9 



59-5 



45-1 



550 



[41-6] 



45-6 



311 



28 



[38-2] 



33-7 



39-4 



[43-0] 



42-8 



511 



[55-1] 



48-6 



51-8 



39-7 



44-0 



' 29-4 



29 



39-9 



34-7 



45-2 



43-6 



43-2 



501 



51-7 



50-9 



[50-5] 



42-9 



40-6 



[31-7] 



30 



35-9 





41-6 



400 



45-7 



[49-6] 



51-0 



53-2 



44-9 



45-2 



36-4 



34-7 



31 



29-0 





[42-0] 





45-5 





53-0 



56-4 





450 





34-0 



Mean 



35-63 



30-84 



3600 



43-17 



44-80 



51-06 



52-16 



51-18 



50-00 



43-41 



40-99 



30-95 



Annual Variation of the Temperature of Evaporation. — This follows the same law as the temperature of 

 the air. The maximum occurs in July and the minimum in December and February. The means for the 

 thermal seasons are as follow : — 



Summer, June, July, Aug., 

 Autumn, Sept., Oct., Nov., 



42°-55 



51°-48 

 44°-72 



Winter, Dec, Jan., Feb., 32°-54 



Spring, March, April, May, 41°-37 



The mean temperature of evaporation for 1 844 



Diurnal Variation of the Temperature of Evaporation. — This, on the whole, also follows the same law as the 

 temperature of the air. The hours of maximum and minimum for the astronomical seasons and for the year, 

 are as follow : — 



Winter. Spring. Summer. Autumn. Year 1844. 



Min. 5 h 10 m a.m. 4 h 30™ a.m. 3 h 30 m a.m. 5 h m a.m. 4 h m a.m. 



Max. l h 15 m p.m. l h 55 m p.m. l h 40 m p.m. l h 40 m p.m. l h 30 m p.m. 



The epochs for the year for the temperature of the air and of evaporation are the same, and they are nearly 

 the same for the quarters. The secondary maximum in winter at midnight is also shewn in the means for the 

 temperature of evaporation. 



The mean tempei'ature of evaporation for the year occurs at 8" 19 m a.m. 

 7 h 32 m p.m. 



The interval between the two periods of mean temperature is ll h 13 m 



