92 CISTERNS. 



and pounded charcoal at the bottom of the former, and 

 sand and gravel at the bottom of the latter. The former 

 will receive the water from the pipe, and it will rise filtered 

 in the latter. 



ANOTHER MODE. Divide the cistern as above by a 

 double open wall of stone or brick, with an interspace of 

 about six inches between the walls. Fill the interspace 

 with sand and pounded charcoal. Let one compartment 

 receive the water, and it will pass through the filter into 

 the other ready for use. 



