TEOPICAL AQUARIUM FISHES 



221 



depth of one foot or more. For tanks of moderate size — say 11x22 

 feet — reinforcement should be by use of ^-inch steel rods, crossed on 

 squares of 8 inches. The bottom needs two layers of these bars, one near 

 the up]ier and one near the lower surface. This protects against both 



Fig. 



161. Correct Arrangement of Reinforcing Steel, and Galvanized Iron 

 Form for Water Lily Pot 



Fig. 162. Wooden Form Ready for Concrete Pouring 

 The dotted blocks represent bricks or stones to hold inside form to same height 

 as the outside. Note slope of inside form. 



