44 THE OASES OF THE NORTH-WEST 



does not compel the communities higher up to respect 

 them. 



Amongst individuals the water-right is generally 

 denned by a measurement of time, a certain number 

 of days or hours during which the owner controls 

 the entire flow of the spring or stream. It is only 

 when the water is more abundant that we find another 

 method of fixing the right of water, defining it by 

 bulk. The water is then said to be demarcada, as the 

 unit is customarily the marco, or the volume which 

 passes through an opening about twenty-one centi- 

 metres in width and eight in height. The marco has 

 infinite divisions, and each subdivision has its own 

 name the naranja, the bombilla, the paja, and so on. 



As all the water is utilized, and the rights of all are 

 equally entitled to respect, the division of the water 

 into marcos (demarcation) is in practice merely a pro- 

 portional distribution of it amongst those who have 

 rights to it. If the sum total of rights expressed in 

 marcos represents something like the total flow of a 

 stream during an average season, in the time of low 

 water it is disproportionate, and the water no longer 

 flows to the tops of the marcos. In other words, the 

 quantity of water granted to each rises or falls with the 

 rise or fall of the stream itself. 



Theoretically, when the water-right is defined in 

 marcos it is permanent. Often, however, it is impossible 

 to grant each proprietor a permanent title to the water. 

 Even in oases where the water is "demarked," the 

 turno that is to say, the turn of the proprietors to 

 have water which is the absolute rule in the poorest 

 oases, reappears during the months of scarcity, in 

 winter, when there is no rain, and at the beginning of 

 summer. It reappears also when the right of owner- 

 ship has been broken up into fractions that are too 

 small, and it is better to grant a larger volume of water 

 for several hours instead of a constant stream of water 

 which would be too scanty for profitable use. At 



