113 



THE LEAN-TO AND THE PAXTONIAN. 



EADEES have frequently asked for further particulars 

 of two plant-houses in the garden at Stoke Newington, 

 which have often been referred to as peculiarly useful 

 and convenient for our experimental purposes. The 

 lean-to occupies the site of a former ditch, and for a 

 special reason was built at so low a level that, in winter, after heavy 

 rains, there is frequently a depth of twelve inches of water on the 

 floor. It is not, of course, recommended that a greenhouse should 

 ever be so built ; I am merely stating the fact, that this was so con- 

 structed for a particular reason. The Paxtonian is on a slightly 

 higher level, and is never swamped. Owing to the low position of 

 the lean-to, it was always considered impossible to heat it, the 

 border on which the plants stand being but a few feet above the 

 general ground level ; and inside the door is a well always full to. 

 the brim, so that it appeared as if a place for a furnace could not be 

 found. There was no place for it except where a constant body of 

 water would render it useless. Hence, for several years, the lean- 

 to was heated with Musgrave's slow-combustion stove, and the Pax- 

 tonian was used for subjects that only required a little shelter. 



It was, however, at last determined to heat these two houses in 

 a manner which would adapt them for stove or greenhouse plants — 

 for any purpose, in fact, which might occur ; and the question arose, 

 in a very solemn manner, how to do it ? A plan was at last matured, 

 simple enough, of course, and with only one nice point worth parti- 

 cular mention, and that was that it depended on a very nice calcula- 

 tion of the vertical space at command, and the squeezing into a 

 space of only two feet vertical height the furnace, boiler, and rise of 

 the pipes in the lean-to — the other house, being on a, higher level, 

 occasioned no difficulty. The form of boiler chosen is called 

 *' conical." It is simply an upright cylinder. The ash-pit is within 



VOL. III. — NO. IT. ^ 



