218 Transactions of the South African Philosophical Society. 



No information is given in the Register concerning the position or 

 mounting of the instruments, or as to what corrections are necessary 

 for index-error; and, indeed, it is not likely that such corrections 

 would make any material improvement. For these reasons it is 

 safer to consider the mean values given below as approximately 

 comparable inter se, rather than as directly comparable with other 

 registers. The following notes from the Inspection Reports of the 

 Cape Meteorological Commission contain nearly all my information 

 about the instruments : — 



1883. — Eortin's Cistern Barometer, set of Thermometers, and a 

 Rain Gauge, all in good order. 



1884. — The Cistern Barometer at this station being found faulty, 

 it was exchanged for the one belonging to the Port Office 

 until a new one could be supplied. All the Thermometers 

 and the Rain Gauge were in good order. 



1886. — The instruments here were in good order. 



1888. — The instruments at this station were all in good order. 

 The exposure of the thermometer, however, in the Stevenson 

 Screen was not good ; it was too close to the ground, and in 

 too confined a spot. I arranged for its removal to a more 

 suitable place. 



1891. — The instruments at East London are in and about the 

 office of the Port Captain on the west or right bank [of 

 the Buffalo River] .... I found the whole in good 

 order and well kept, and the records neatly made up to 

 date. 



There is also a note in the Report for 1896 to the effect that the 

 index error of the Barometer = + '012 inch. 



In addition to this, Mr. S. R. Pockley, the Secretary to the 

 Harbour Board, informs me that "the distance of the thermometer 

 screen from both sea and river is about 150 feet, and about 45 feet 

 above mean sea-level. There has been no material alteration in the 

 position of the instruments during the period January 1, 1884, to 

 present date." 



With regard to the dates, it should be remembered that the values 

 of maximum and minimum temperature and rainfall are for the 

 24 hours ending 8 a.m. of the date of entry, the first and third 

 not having been credited, as is usual in England, to the previous 

 day. 



The approximate monthly mean and extreme barometric pressures 



