330 Memoirs of the Caledonian Horticultural Society. 

 L .1 



a, Stage for plants. b, Arched wall for support of stage. c, Arched wall and back flue. 



d, Raised walk, or gangway, in front of stage. e, Arched wall for support of walk. 



/, Arched wall and front flue. g, Peach trellis. k, Stone for support of peach trellis. 



*c, Made border for vines : it is 14 ft. wide, 5 ft. deep at back, and 3 ft. at front. Here the vines 



are planted against the back wall, and trained down the rafters, one branch to each, on the 



spur mode of pruning. 

 k, Peach border within and without the front wall. 

 I, Front shelf, for forcing strawberries, &c. 



72. Account of a Mode of producing a steady and uniform Bottom 

 Heat in Pine-apple or Melon Pits, or in Stoves for Exotic Plants^ 

 by means of Steam introduced into a close Chamber filed tvitk 

 JVater-worn Stones. By Mr. John Hay, Planner, Edinburgh. 

 Read March 5. 1829. 



We have already (Vol. V. p. 443. and 450.) noticed this 

 important improvement in exotic culture ; and stated that 

 the first idea of applying steam to the heating of hot-houses 

 occurred to Mr. Hay about the year 1794. In 1807, a pine- 

 stove was designed and executed for the Duke of Northum- 

 berland, at Alnwick Castle, by Mr. Hay, in which a chamber 

 below the bark-bed was rilled by stones heated by steam ; but, 

 as the pipes and supply of steam were too small for the mass 

 of stones, the use of this mode of heating was in this instance 

 not long continued. Mr. Hay did not, however, lose sight 

 of the principle ; and accordingly, in 1818, applied it in small 

 pine-pits at Castle Semple, and in pine-stoves at Bargany. 

 About the end of the year 1820, Mr. Hay says : — 



