ABSTRACT
Float driven chart recorders , originally in t roduced in the middle of the n ine teen th century, cont inue to domina te stage recording on a world-wide basis (Figs 3 .10 and 3.11 in Chapte r 3 ) . In a few countr ies , however , whe re for various reasons s o m e rivers may not permit automat ic cont inuous recording (e.g. extens ive m u d flats at low water) , the reference gauge m a y be manual ly read at predetermined t imes (e.g. half-hourly, hourly, daily, e tc . ) and each stage value conver ted on site to discharge us ing a rat ing table.
