48 Transactions of the South African Philosophical Society. 



Of the last little need be said. They are troublesome to use as 

 routine instruments, but they may be safely trusted to evaporate 

 more water in a given time than any other evaporator in 

 use. 



Comparative monthly totals for the year 1900 are : — 



January . 

 February . 

 March . . . 



April 



May 



June 



July 



August . . . 

 September 

 October . . . 

 November 

 December . 



Year . 



8-inch 

 Copper Pan. 



Screened 

 Tub. 



Tank. 



Piche Tube. 



Inches. 



Inches. 



Inches. 



Inches. 



11-57 



7-11 



7-58 



8-59 



11-26 



6-73 



6-78 



8-62 



6-35 



3-72 



4-28 



5-28 



415 



2-61 



2-95 



3-79 



419 



3-08 



2-44 



5-13 



3-14 



2-35 



1-60 



3-94 



2-93 



1-94 



1-37 



3-37 



5-06 



3-29 



2-77 



5-73 



8-81 



6-55 



4-73 



9-48 



10-93 



8-06 



6-23 



10-32 



12-49 



9-65 



7-74 



11-26 



9-94 



6-89 



6-74 



7-32 



90-82 



61-98 



55-21 



82-83 



The daily mean values are 



January . , 

 February 

 March . . 

 April .... 

 May .... 

 June . . . . 

 July .... 

 August . , 

 September 

 October . . 

 November 

 December 



Year 



8-inch 

 Copper Pan. 



Inches. 

 •373 

 •402 

 •205 

 •138 

 -135 

 •]05 

 -095 

 -153 

 •294 

 •353 

 •416 

 •321 



•249 



Screened 

 Tub. 



Inches. 

 •229 

 •240 

 •120 

 •087 

 •099 

 •078 

 •063 

 •106 

 •218 

 -260 

 -322 

 •222 



•170 



Tank. 



Inches. 

 -244 

 •242 

 •138 

 •098 

 •079 

 -053 

 •044 

 •089 

 •158 

 •201 

 •258 

 •217 



•151 



Piche 

 Tube. 



Inches. 

 •277 

 •308 

 •170 

 •126 

 •165 

 •131 

 •109 

 -185 

 •316 

 -333 

 •375 

 •236 



•227 



Comparative daily extreme values chiefly, l)ut not necessarily, 

 occurring on the same day, are : — 



