62 Airpcndices to Eighth Annual Report of Fishery Board for Scotland. 
the trough so that the pass may remain open much longer than the time 
it is shut. 
The whole work to be painted a dark green colour. 
The pass and sluice, &c. may be wholly constructed of iron. 
The sides and top of the pass may be built of stone or concrete, and the 
sluice and uprights, &c. made of iron or wood. 
The pass and sluice, &c. may be constructed of any combinations of these 
materials. 
EDINBURGH : PRINTED BY NEILL AND COMPANY 
FOR HER MAJESTY'S STATIONERY OFFICE. 
