586 



TROPICAL HYGIENE, SANITATION, ETC. 



(4) Deep Trenches. — These are often used, but are very un- 



satisfactory and should be condemned. They are 3-4 

 metres deep, 1-2 metres wide, with sticks thrown across 

 at intervals. The sides are nearly always fouled. 



(5) Prepared Trenches. — These are useful in certain instances 



close to works for the use of the native workmen. The 

 floor of the latrine is covered over with dry earth, the 

 excreta covered with another layer immediately, and the 

 whole removed daily. Constant attendants are required. 



A double public latrine. 



Exposure to the sun is advantageous, but rain and flood 

 water must be excluded in the rainy season. 



(6) River Latrines. — These are often used by companies for 



their employees, but the practice fouls the river banks 

 and the river bed at low water, and in any case pollutes 

 the water for the villages downstream. The practice 

 should be condemned. 



(7) Deep Pit Latrines. — For better class natives one has found 



useful a latrine as follows : A hole is dug about 6 

 metres deep and 0*5 by 075 metres in diameter. A box 

 seat is fixed over it with a lid to make it fly-proof. A 

 small house with a locked door is built over this, say of 

 corrugated iron and made movable. 



