RESEARCH IN SIERRA LEONE. 



159 



November, it was actually higher). In other words, the humidity on the coast is 

 more evenly distributed throughout the year, and a diminution in the rainfall in 

 that region does not involve a corresponding diminution in humidity. 



Table E. 

 Number of days on ivhich Rain fell in Freetown in 1911. 





Jan. 



Feb. 



Mar. 



Apr. 



May 



June 



July Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Total. * 



1905 

 1906 

 1907 

 1908 

 1909 

 1910 

 1911 

 1912 



2 



2 

 2 



3 



2 



1 

 2 



2 



2 

 8 

 3 

 1 



3 



6 



3 

 6 

 4 

 6 

 2 



12 

 22 



17 

 21 

 15 

 18 

 11 



27 

 24 



22 

 23 

 24 

 29 



26 



25 

 26 



20 

 29 

 31 

 30 

 30 



27 

 23 



24 

 29 



30 

 30 



24 



23 

 21 



29 

 26 

 24 

 26 

 21 



21 



19 



23 

 23 

 23 



27 



18 



12 

 6 



11 



16 

 11 

 11 



8 



3 



10 



4 

 5 

 3 

 3 



155 



152 

 160 

 151 



189 

 170 

 184 

 145 



Table E gives the number of days on which rain fell in Freetown from 1905 

 to 1912, with the exception of 1907, and shows that with few exceptions the 

 number of rainy days is fairly constant. It will also be seen from this table that 

 the months of June, July and August may be regarded as the period of heaviest 

 rainfall. 



The following table for 1911 will serve to emphasise in a graphic manner some 

 of the deductions from the foregoing tables. 



Table F. 





Freetown. 



Bo. 



Batkanu. 



Daru. 



Kaballa. 



Greatest amount of rain on one day 

 Highest Temperature recorded ... 

 Lowest Temperature recorded 

 Greatest diurnal variation... 



7-47" 

 96-4° 

 65-8° 



7-08" 

 99° 

 52-8° 

 34-8° 



4-58" 

 92-8° 

 60° 

 26-6° 



2-45" 

 97-8° 

 55° 

 33-4° 



2-25" 



100° 



41° 



57° 



III. Narrative. 

 (1) Freetown to Port Lokko, Kaballa and back to Port Lokko. 



This journey was accomplished between 19th March and 30th April 1912, 

 i.e., towards the end of the dry season when insect life is at its minimum. Con- 

 sequently, it must be remembered that the number of species or even the number 

 of specimens of any one species cannot be taken absolutely as a criterion of 

 prevalence. A glance at the map will show that the records for Glossina on this 

 trip are much fewer than on any succeeding journey, but at the same time there 

 is little doubt that many more of the different species would have been found a 

 month or two later. 



The journey from Freetown to Port Lokko is made by steam-launch up what 

 is known as the Sierra Leone River. In the early part, this waterway is very 



