332 Memoirs of the Calcdoninn llorlicuUnral Society. 



" A B c u, The external walls of the pits, built of droved ashlar, 8 in. 

 thick. In the upper course of ashlar, on both sides, arc gutters for carrying 

 ort" the rain-water from the roof sashes. The drawing is 10 ft. over the 

 walls. 



" E, An elevated walk, with steps, on which the gardener may stand with 

 case, and do any work in the pits, v, a step for the same purpose, g, a 

 paved or gravelled walk. 



" u I K I,, Wall of stoam-chamlicr \\ in. thick, of square stock bricks, 

 closely jointed with Roman cement. 



