JAKOB SCHETELIG. 



Date 



5 17-5=0. 

 17-5' C. 



Interval 

 between 

 Determi- 

 nations 



17-5-C. 

 »^ 175"C 



Differ- 

 ence 



Increase 

 per hour 

 by Eva- 

 poration 





Oct. 29, 1 

 1900 2 



1-02669 

 2669 



li hr. 

 16 hrs. 



1-02671 

 1-02683 



0-00002 

 0-00014 



0-0000133 

 0-0000088 



Day-time. 

 Day & night. 



March 5, 3 

 1901 4 



1-026825 



26825 



3 hrs. 



48 „ 



1-026860 

 1-027100 



0-000035 

 0-000275 



00000117 

 0-0000057 



Day-time. 

 Day & night. 





Mean 



0-0000099 



per hour. 



No notice is taken here of the temperature of the atmo- 

 sphere, and its degree of moisture; but the conditions in the 

 laboratory were very much the same from day to day, so that 

 in its main features the experiment nevertheless shows the amount 

 of evaporation. I have thought, at some future time, of more 

 thoroughly investigating the rate of evaporation of sea-water, 

 and obtaining more reliable figures. 



As the table shows, the rate of evaporation is more rapid 

 in the day-time than at night. There was no fire at night, and 

 the temperature sank considerably. 



All determinations were made in the day-time, in a room 

 with a temperature of about 16 to 18° C. Every hour that the 

 cylinder stands uncovered, the evaporation will increase the 

 specific gravity of the sea- water sample by rather more than 

 O'OOOOl, that is, taking only experiments 1 and 3 into considera- 

 tion, which show the rate of evaporation in the day-time (mean 

 of experiments 1 and 3 = 0'0000125 per hour). In experiments 

 2 and 4 the sample was left all night as well. 



In accordance with this, the 2nd determination of water- 

 sample gives, as a rule, a rather higher specific gravity than 

 the 1st determination of the same sample. Out of 24 2nd deter- 

 minations, the majority show a higher specific gravity than their 

 1st determination, and the mean difference is 0000008, 



