69G 



EEPORT — 1901. 



The prevention of malaria and other mosquito-borne diseases. Punliahs, 

 mosquito-nets, wire gauze, and quinine. Segregation. Koch's method. 

 Necessity for ridding towns of mosquitoes. Experiments now in progress in 

 Sierra Leone and Lagos. 



6. Exhibition of Photographs of Fossils in the La Plata Museum, 

 By Dr. Francisco P. Moreno. 



A New Sounding and Ground-collecting Appara'ua, 

 By Professor G. Gilson, of Louvain. 



Side Yiew, showing method of suspension. 



Front view, showing mechanism. 



c::::::'!::::^^ 



■br 



h, Imndle suspending block h ; h, cast-iron block ; hi; steel bar ; cp, cup ; c, cover ; 7?, ring 

 keeping apparatus in an oblique position when lying clown on the bottom. Tliis ring is attached 

 to tlie block b and moves with it ; m, mechanism intended to release the cover c when the appa- 

 ratus is hauled up, and not before that. 



The cam seen at the lower part faUs as soon as the cup cp strikes the bottom, the block 6 

 sliding down then to the table I. This cam is fixed to a flat iron piece with a catch on its right 

 side to suspend the cover c. The upper part of this piece is engaged, on the left side, in a groove 

 cut in tlie vertical rod. When the block 5 is lifted up, the cam not being in place, the end of the 

 groove catches, and the cover c is released by the swinging of the flat piece. 



