8S9.] 



Africa from Barometric Observations. 



323 



Heights calculated by the foregoing Table, from the average Baro- 

 metric Pressure during the eleven years from 1881 to 1891 

 inclusive. 



Station. 



Average 

 Barometric 



Calculated 

 Height. 



Height 

 otherwise 



Differ. 







pressure. 



determined. 





* 



Simon's Town .. 



30-056 



21 







Cape St. Francis 



30-056 



21 



20 



+ 1 





East London ... 



30-044 



33 



30 



+ 3 



*(«) 



Royal Observatory 



30-040 



37 



37 







*- 



Cape Agulhas ... 



30-009 



6Q 



55 



+ 11 



(b) 



Mossel Bay 



29-963 



111 



105 



+ 6 



i'f 



Port Elizabeth .. 



29-887 



180 



181 



- 1 



^;= 



Dunbrody 



29-851 



214 



200 



+ 14 





Clanwilliam 



29-808 



254 



245 



+ 9 





Wynberg 



29-811 



251 



250 



+ 1 





Wellington 



29-640 



413 



400 



+ 13 





Swellendam 



29-569 



479 



475 



+ 4 





Oudtshoorn 



28-928 



1081 



1063 



+ 18 





K. Wm's. Town 



28-683 



1329 



1314 



+ 15 





Ceres 



28-491 



1516 



1493 



+ 23 





Lovedale 



28-281 



1723 



1720 



+ 3 





Graham's Town 



28-146 



1856 



1851 



+ 5 



* 



Prince Albert 



27-887 



2115 



2120 



- 5 





Somerset East ... 



27-597 



2408 



2400 



+ 8 





Graaff-Reinet ... 



27-486 



2519 



2500 



+ 19 





Stutterheim 



27-347 



2661 



2700 



- 39 





Cradock .. ... 



27-169' 



2845 



2856 



-11 



# 



Queen's Town ... 



26-445 



3597 



3543 



+ 54 





Brakfontein 



26-117 



3946 



3947 



- 1 





Kimberley 



26-031 



4038 



4042 



- 4 



* 



Aliwal North ... 



25-762 



4328 



4330 



- 2 



* 



Bloemfontein 



25-583 



4524 



4518 



+ 6 



* 



Sutherland 



25-315 



4818 



4776 



+ 42 





The results indicated by * are those which have been brought to the test by railway 

 levelling and it will be seen that the average error is about 6 feet on either side. One 

 source of error which the writer has not been able to eliminate is the existence in 

 some cases of undetermined and uncorrected index error in the various instruments 

 used. This will, it is expected, cease to affect the observations made in forthcoming 

 years, since these index errors are now ascertained in almost [all the instruments, and 

 no doubt will in future be systematically applied. 



Note a. For about half the period, the barometer at East London was at a 40 feet 

 level, for the other half at 20 feet. 



Note 6. The true level of the Agulhas Barometer is in doubt, it was estimated a 

 few years ago at 68 feet. 



