ox THE CLIMATOLOGY OF AFRICA. 



417 



Variations in the Level of Victoria Nyanza. 



Lake Level 



Bain 



•Decades 

 1S9S 



January, • I. 



II. 



III. 



Februarr, I. 



II. 



III. 



Ivlarch, I. 



II. 



IIL 



I. 



II. 



III. 



I. 



IL 



III. 



I. 



IL 



III. 



I. 



II. 



III. 



August, I. 



IL 



III. 



September, I. 

 IL 

 III. 



October, I. 



IL 



III. 



November, I. 



II. 



IIL 



December, I. 



II. 



III. 



April, 



May, 



June, 



July, 



Port 

 Alice 



In. 



7-8 

 7-1 

 G-1 

 5-7 

 4-6 

 2-9 

 1-9 

 1-1 

 2*2 

 2-7 

 3-2 

 3-9 

 3-5 

 2-9 

 2-5 

 11 

 1-2 

 2-1 

 2-2 

 •7 

 •0 



- 0-6 



- 1-0 



- 13 



- 3-8 



- 5-1 



- 5-9 



- 7-5 

 -10-0 



- 9-8 



- 8-6 



- 4-4 



- 2-3 

 0-9 

 2-1 

 2-2 



Year (Mean) 



1897 

 Januai-y, I. 

 II. 

 IIL 



Tebruary, I. 

 II. 

 III. 



Lubwa 



0-0 



30 

 2-7 

 1-9 

 3-0 

 2-U 

 1-7 



In. 



4-4 

 3-3 



2-5 

 2-2 

 3-3 

 3'2 

 2-3 

 3-9 

 3-4 

 3-0 

 4-2 

 3-7 

 2-9 

 2-2 

 2-3 

 1-2 



- -2 

 -1-2 

 -2-1 



- -8 

 -1-5 

 -2-8 

 -4-1 

 -G-1 

 -7-0 

 -8-7 

 -8-8 

 -8-7 

 -4-2 

 -1-7 

 -2-3 

 -2-2 

 -3-4 



0-0 



Port 

 Vic- 

 toria 



-3-5 



-2-5 



-2-6 



-1-50 



--0-80 



-1-96 



In. 



6-9 



G-7 



6-3 



5-9 



4-3 



3-6 



2-8 



3-5 



3-4 



2-2 



3-4 



3-4 



3-4 



3-3 



2-8 



2-4 



2-5 



2-1 



1-2 



- -1 



-1-7 



-2-3 



-2-4 



-2-0 



-4-1 



-5-2 



-6-7 



-7-3 



-8-8 



-9-7 



-7-6 



-2'7 



-1-0 



-17 



-2-7 



-2-4 



Port Alice 



Amt. 



In. 



Days 



0-0 



15-40 



3-90 



3-17 



-85 



2-33 



1-27 



2-46 



•26 



•46 



•08 



•20 



•03 



2-04 



2-06 



■00 



•20 



•87 



1-30 



•38 



1-34 



2-87 



3-66 



7-21 



1-18 



3-4G 



•97 



•21 



Port 

 Vic- 

 toria 



Days 



-3-5 

 -2-1 

 -1-9 

 -1-55 



- -17 



- ^44 



•08 



•47 



1^20 



1-21 



•59 



1-82 



2 

 1 

 2 

 3 

 6 

 10 

 8 

 7 

 4 

 3 

 3 



Months 



1896 

 .Innuary . 

 February . 

 Marcli 

 April 

 May. . 

 June 

 July 



Aupust . 

 Seiitember 

 Octolier . 

 N vember 

 December 



Year (Mean) 



1897 

 .January . 

 February 



i897. 



Notes. 

 The oh.ser%'ations on the rise ami fall of the 

 level of Victoria Nyanza were begun in January 

 1896 by direction of Sir Ernest J. L. Berkeley, 

 H.M.'s Commissioner, who placed this work 

 under the charge of Mr. R. J. D. Macallister. 

 There are at present three stations : — • 



Port Alice, or Ntebe, the Lake Port of the 

 capital. The observations are made daily at 

 noon. The observers were Major A. E. Smith 

 (January), Mr. Alex. Geo. Boyle (February to 

 September), and Mr. Fred. Pordage. 



Lubu-a, near the outlet of the Victoria Nile. 

 Observer, up to the beginning of February 1897, 

 Mr. \V. Grant. 



Port Victoria, on Berkeley Gulf, in the N.E. 

 corner of the lake. Observer, up to the end of 

 1896, Mr. K. J. D. Macallister ; since that time 

 Mr. C. W. Fowler. 



At Lubwa and Port Victoria the observations 

 are made at 9.30 a.m. Observations on the rain- 

 fall are made at Port Alice only, no gauges being 

 available. 



Care has been taken, when fixing the gauges, 

 to prevent a subsequent settlement. 



On beginning their work the observers were 

 of necessity compelleil to choose an arbitrary 

 datimi level. In our abstract the datum level ac- 

 cepted is the mean level of the lake during 1896. 

 In the accompanying tables the results are 

 given by decades, and also by months. 



In examining this interesting record it will 

 be found that the influence of the raiiifall 

 upon the level of the lake is not so immediately 

 apparent as might have been expected. Thus, 

 a rainfall of 2-3G in. on November 14, 1896, only 

 caused a rise of tlie lake to the extent of 0-75 in., 

 and the heavy rainsduriug October and Novem- 

 ber (16-64 in.) influenced the lake level to the 

 extent of only about 5 in. Evaporation, no 

 doubt, as also the irregular distribution of the 

 rains over a lake covering an area of 25,000 sq. 

 miles, go far to explain tills. 



The winds exercise a decided influence upon 

 the level. They are regular land and lake breezes, 

 blowing olE-siiore ( from the E. or N.E.) in the 

 morning, and changing about noon to W. or S.W. 

 The lake breezes are more especially important, 

 and Mr. Macallister remarks that a strong S.AV. 

 breeze will cause a rise in the level of the lake 

 to the extent of from 1 to 3 in. 



As the observations at two of the stations are 

 made in the morning the actual mean level 

 is probably a little higher than it is made to 

 appear from our abstract. In order to trace the 

 influence of the wind upon the lake level it would 

 be necessary to establish a self-registering 

 gauge or to make observa- 

 tions at least thrice daily. 

 Taking the mean of the 

 three stations we find that 

 on January 1 thelevelstood 

 7-8 in. above the datimi, 

 whilst on December 31 it 

 was 3'3 in. below it, a differ- 

 ence of 11-1 in. The level 

 was highest in the begin- 

 ning of the years, lowest 

 (—9-2 in.) during the 2nd 

 decadeof October. The ex- 

 treme range amounted to 

 18-2 in. (Port Alice 19-0 in., 

 Lubwa 17-0 in.. Port Vic- 

 toria 18-2 in.) 



It is desirable that simi- 

 lar observations should be 

 made on the S., E., and W. 

 shores of thelake. The con- 

 nection of the^e stations by 

 lines of spirit levelling can 

 hardly be looked for for 

 many years to come. 



E E 



