struction to the others is specially used for the purpose of 

 heating these. It is fixed in the same stoke-hole, and close to 

 those before described, but in no way connected with them. 

 There is a main piipe leading from the top of the boiler, along 

 the passage at the back, and beneath the gallery floor. This 

 main is at equidistant points intercepted by the inseiliion of an 

 extra-stout junction casting, which is employed for the purpose of 

 comiectiag the ornamental pedestals fixed above the floor-line. 



The quantity of piping in the Conservatory is about 9000 feet, 

 in addition to various connections. The hot-water pipes beneath 

 the ground-floor run in groups of 6, 8, and 10 respectively, in 

 trenches varying from 2 feet to 3 feet wide, by about the 

 same depth. On the level of the floor is a series of ornamental 

 cast-iron gratings, through which the heated air ascends. These 

 con-espoiid to the gratings in other parts of the floor, through 

 which the cooler air descends, and is conducted beneath each 

 separate set of pipes. The gratings communicate directly with 

 the circulating air-drains, and by this means the entire appa- 

 ratus is kept in working order. 



No dust, efliuvium, or oilensive vapour is generated by this 

 apparatus : it produces perfect ventilation with uniform heat 

 throughout the budding, and for horticultural and other pur- 

 poses it is commendable for its economy, its cleanliness, and its 

 durability. 



The heating of the Conservatory has been executed by 

 Messrs. "Weeks, of Chelsea, with whom several of the devices 

 above mentioned originated. 



i 



