( 7 ) 



X. lu some rivers, ns (lie Trrawadi or the Indus, a 



II„w rivers W. heir scn.n„s ^'^^^^^^ dKrcreut statc of things is 



oriniiiiiintinnR,flnoiUiio country, pcrcGivcd. Ill tlic latter rivcr its 

 '^^fVIZZ'^i!:^ mH::^ gi-e^^test height is about August, and 



ill portions of the Punjab and in thls is the pcrlod of Ucaviest floods ; 



^""'" in September its subsidence is usually 



very rapid, zero being commonly reached by November. As 

 a large tract of country becomes inundated during these 

 periods of floods, the tanks, to wherever tlicy extend, receive a 

 fresh supply of water : in Burma, where this occurs, due to 

 the risings of the Irrawadi or Pegu rivers and the downpours 

 of rain, these tanks are termed Eens, whilst in a portion 

 of the ranjab and in Sind, where the Indus extends, the local 

 term Dhdnd is employed. 



XI. These tanks or dhdnds in Sind, that arc useful to 

 mands or tanks in Sind mnin. fishcrmen, are of twoclasscs : the 



Iv divisililo into isolated ones, in fu'St arC isolated dJu'tuds, and lu 



::^:X::::ZZ:^:=l ^-''iel^ communication with the Indus 



ium^, mA connected o\\Q%, wliiuh Ollly OCCUrS (lurillg pCl'iods of illUU- 



into a tank, and tl.nir comnn.ni- datlOUS, aud mOStly driCS Up J)riOr to 

 cation continncs tlirongliont or tllC UCXt ycar's SUpply ; wllilst tllG 

 for the most part of the year. geCOml are COUUCCted dhdllds, bciug 



expansions of a river, small stream, or cannl into a tank, and 

 which, throughout or for the most ])art of the yeai', are con- 

 nected Avith running water. Some of these dhdnds arc 

 without, others within, embankments, which have been 

 constructed for keeping tlie inundation water within duo 

 limits, or bunding it in certain desired directions. 



Irrigation Works. 



XII. Amongst the artificial causes affecting fisheries 

 are anicuts, weirs, or bunds constructed for the purpose 

 of irrigation or working mills. Irrigation weirs have been 

 erected across various rivers in the Panjab, North-AVestern 

 Provinces, Pengal, aud Madras, in order to deflect a certain 

 amount of water into canals constructed for its reception 

 and dissemination. These weirs are usually built in the 

 form of stone Avails across the entire breadth of rivers, 

 and consequently form an obstruction, arresting the up- 

 Avard and doAVUAA^ard passage of fish that arc endeavouring 

 to migrate, AAdiilst, should it be sutTiciently high, it entirely 

 prevents their passing. On the bed of the river iu front 

 of it, or on its down-stream face, there is generally a stono 

 ])avemcnt termed "an ai)ron," or this apron may be a gradual 

 slope of rough or smooth stones extending from the summit 



