2 Transactions of the South African Philosophical Society. 



however, what might be called a "roof" exposure, at an elevation 

 of about 15 feet. This seems to have resulted in a small loss in the 

 catch. Still an elevated gauge at Kimberley would not lose so great 

 a percentage of the total fall as one at the same altitude in England, 

 since our winds are lighter, and the average size of the raindrops 

 much greater. Small droplets are readily carried by strong winds, 

 -as is proved by the "salt rain" (really sea spray) occasionally 

 reported from different parts of inland England. * The Matthews 

 gauge is a 5-inch Symons's early pattern. 



No. 2 had also a roof exposure at nearly the same height. The 

 gauge is an 8-inch Meteorological Office pattern. In earlier years 

 the catch was entered to the ninth decimal place ! This unique 

 effort seems to have been accomplished by weighing the catch and 

 converting ounces and grains into inches. But even if the mouth of 

 the gauge had been accurately measured, the quantity of dust and 

 rubbish collected would probably have been fatal to the trustworthi- 

 ness of anything after the third decimal place. As a matter of expe- 

 rience, weighing is not to be recommended, with or without the 

 extra decimals. " Weighing the water," said Horsley, " and reducing 

 it from weight to depth, seemed pretty troublesome even when done 

 in the easiest method." \ 



No. 3 is a Glaisher 8-inch gauge. Up to 1889, when the De 

 Beers Company took over the business of the Exploration Company, 

 it stood about 4 feet above the ground in a small courtyard behind 

 the offices in Lennox Street. Now it is being used in the west end 

 of Kimberley. I have some indistinct idea that the mouth of the 

 gauge was said to be slightly too large, although it would be less 

 surprising to be told that it had become too small, such being the 

 •certain ultimate fate of every gauge ; for with a given perimeter a 

 circle encloses the greatest area, and therefore any deformation of 

 the rim of a gauge means a reduced area of catch. For a nice proof 

 see Halsted, Elements of Geometry, p. 162. 



Like a number of other gaols in the country, the rainfall reported 

 by No. 4 is less than that reported outside. The inference that rain 

 does not therefore fall upon just and unjust alike is plausible but 

 incorrect. The true explanation is that the lighter rains are ignored 

 by the observer. 



No. 5 is an 8-inch ordinary gauge, mounted with its rim 3 feet 

 above the ground. The observations with this have been supple- 

 mented by the hourly totals of rain caught in a large evaporation 



* See e.g., Phil. Trans., 1704, passim) Luke Howard, Appendix to Barometro- 

 jjraphia, part 2, p. 16a. 

 f PMl- Trans., 1723. 



