Malaria Bureau, Issue 3Manager of Publications., 1960 - Malaria |
From inside the book
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Page 21
... drain should be rounded and not V - shaped , but in broad drains a shallow V is preferable to a flat bottom . In the case of hill - foot seepages , the best method is to construct a system of contour drains , at right angles to the ...
... drain should be rounded and not V - shaped , but in broad drains a shallow V is preferable to a flat bottom . In the case of hill - foot seepages , the best method is to construct a system of contour drains , at right angles to the ...
Page 22
... drain has to pass beneath a road by means of a culvert the grade of the drain should be increased , to prevent the accumulation of silt or débris . The bottom of the culvert should be lined with stone or concrete . A screen of vertical ...
... drain has to pass beneath a road by means of a culvert the grade of the drain should be increased , to prevent the accumulation of silt or débris . The bottom of the culvert should be lined with stone or concrete . A screen of vertical ...
Page 23
... drains . These are left open for 6 months , being oiled at intervals if found necessary . During this period , the subsoil water level falls , and an opinion can be formed as to the exact depth necessary for good drainage . The central ...
... drains . These are left open for 6 months , being oiled at intervals if found necessary . During this period , the subsoil water level falls , and an opinion can be formed as to the exact depth necessary for good drainage . The central ...
Contents
PART IIMEASURES DIRECTED AGAINST ADULT MOSQUITOES | 7 |
Drainage | 24 |
Chemical Larvicides | 30 |
3 other sections not shown
Common terms and phrases
aldrin alkali allethrin anophelines ANTI-MOSQUITO applied Bombay boom bottom breeding places canal cattle cent channel chemical chlordane chlorinated hydrocarbons compound containing control of mosquito cresol dehydrochlorination Delhi diameter diazinon dieldrin Dimethyl phthalate dosage drain drainage effective embankments emulsifiable concentrate emulsion Ethyl feet formulation gallon Gambusia gamma BHC gamma isomer gauze hole inches India insecticides insects irrigation isomer large number larvæ larvicidal oils larvicides larvivorous fish lethal lindane malaria malaria control Malaya measures method mosquito breeding mosquito control mosquito larvae nozzle obtained paraffin parathion paris green piperonyl piperonyl butoxide pipes poisoning pond pools possible Post Box practised prevent pyrethrins pyrethrum repellent residual sprays resistant to DDT screening seepage silt sluice soaked soluble solution solvents species sprayer stones stream subsoil water suspension swamp tion Toxaphene toxicity treated trees usually vegetation vermiculite volatile water dispersible powders water level whilst wire workers