32 DATE VARIETIES AND DATE CULTURE IN TUNIS. 



is laid across the canal to form the dam is divided into a series of 

 long, shallow notches, separated by narrow ridges. The number of 

 notches in each dam corresponds to the number of parts into which the 

 stream is to be divided at that point. Thus, if three-fifths of the water 

 is to be diverted into one of two branches and two-fifths into the 

 other, five notches are cut, the water passing over three of them 

 going to the first branch and the rest to the second. The notches 

 being all of the same length and depth, the division is quite accurate. 

 Divisions of the main stream down to the twenty-first part of the 

 total flow are not transferable, belonging for all time to the same 

 district of the oasis. Smaller fractions of the water, however, can 

 be alienated, and there is much bartering of water rights among the 

 different proprietors of gardens. 



At all the principal diversion dams, guards are stationed day and 

 night to prevent any tampering with the water, there being three 

 guards at the first diversion and two at each of the other important 

 ones. These guards are paid with a bunch of Fteemy dates from each 

 garden that receives water passing over the dam they tend, those at 

 the first diversion being entitled to a bunch from every garden in the 

 oasis. The '' amin," " or exj^ert, who supervises the entire system has 

 also the right to select a bunch of Fteemy dates from every garden, 

 his being the first choice after the '' khammes," or tenant, of the 

 garden. 



The principal canals are kept up by assessment upon all the owners 

 of gardens supplied by them. Smaller ditches (seguias) must be 

 kept in order by the tenants of the gardens served by them, and it ds 

 also the duty of the khammes (tenant) to be on hand at the small 

 dam which diverts water into his ditch when it is the turn of his 

 garden to receive water, for there is a fixed hour for the irrigation 

 of each garden. 



The method of measuring time in connection with this irrigation 

 system is an interesting one. A metal cup-like receptacle, called a 

 "■ gadous,"' is filled with water and hung up in a convenient place by 

 the dam. The bottom of the receptacle is perforated, and the hole 

 is always of the exact size necessary to let all the water run out in just 

 five minutes. The water that runs over a notch in the dam during 

 the time required for the gadous to empty eleven times (hence, in 

 fifty-five minutes) is sufficient to irrigate thoroughly a garden of 

 2.4 acres (1 hectare), the length of the notch being fixed and its 

 depth corresponding to the velocity of the current. 



"The " amins " (pronounced " ameens ") are selected from among the older in- 

 habitants of the community for their l^nowledge of agricultural matters. 

 Their function is to act as arbiters in disputes concerning water rights, the rela- 

 tions between proprietors and tenants, the sale of agricultural products, etc. 



92 



