8 9 



PROGRESS OF CAMPAIGN. 



The Culex gang, under a native headman, did very rapid work. 

 They piled the rubbish into carts, which then discharged it into an 

 assigned rubbish shoot. At the same time they showed the larvae to 

 occupants of houses and instructed them in the manner of destroying 

 them by emptying the vessels which contain them, or by dropping a 

 little oil on the surface of water in which they live. It was found that 

 on the average this gang cleared about fifty houses, and removed 

 about ten cart-loads of empty tins and broken bottles daily. The 

 effect of this work on the prevalence of Culex and Stegomyia can 

 be imagined when it is remembered that about one-third of the tins 

 and bottles contained the larvae at this season (the rains). Every 

 house had previously been breeding mosquitoes in its own backyard 

 or garden. The occupants welcomed the gang wherever it went, and 

 some stated that they had not been able to get rid of their rubbish for 

 years. 



The Anopheles gang had a more difficult task. The breeding- 

 pools of these insects in Freetown, both in the rains and the dry 

 weather, have been minutely described by two previous scientific 

 expeditions.* At this season the water courses contained impetuous 

 torrents too rapid for larvae to live in ; but the streets, yards, and 

 gardens possessed numerous pools of rainwater, well suited for them. 

 These were attacked by many methods. Some were filled with earth, 

 rubble, and turf. Others were evacuated by cutting through the rock 

 which contained them, or by making channels in the soft earth. 

 Owing to the large rainfall (estimated at about one hundred and sixty 

 inches annually), to the peculiar nature of the ground, and to the very 

 defective surface drains, these puddles were exceptionally numerous 

 in Freetown ; and, in order to drain many of them as soon as possible 

 it was deemed advisable to adopt the simplest and least expensive 

 methods at first, and to reserve more permanent works for the future. 

 At the same time several men were specially employed in brushing 

 out with brooms, or treating with crude petroleum or creosote, those 

 puddles which the workmen had not yet had time to touch. Progress 

 was fairly rapid in spite of the deluge of rain ; and many of the worst 

 streets were fairly well drained in a few weeks. 



* Report of the Liverpool Malaria Expedition to Sierra Leone, University 

 Press, Liverpool, 1900 ; and Reports of the Malaria Committee of the Royal 

 Society, Harrison and Sons, St. Martin's Lane, London. 



