332 Memoirs of the Caledonian Horticultural Society. 



"abcd, The external walls of the pits, built of droved ashlar, 8 in. 

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

 off 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 

 ease, and do any work in the pits, f, a step for the same purpose, g, a 

 paved or gravelled walk. 



" h i k_l, Wall of steam-chamber H in, thick, of square stock bricks, 

 closely jointed with Roman cement. 



