218 



HEATING AS APPLIED IN HORTICULTURE. 



Tysson states, that " the great advantage 

 of this stove is the extreme purity of the 

 air conveyed by it, either to a conserva- 

 tory or dwelling-house. By experiments 

 tried by a hygrometer, it appears, when 

 heated, to retain the same degree of mois- 

 ture as the outer air ; at least, the hygro- 

 meter varies in the house according to 

 the outer damp, and the steam has never 

 been required in the conservatory from 

 any dryness proceeding from the warm 

 air." This we can only say, if correct, is 

 rather extraordinary ; for air made to 

 pass over dry heated bodies must and 

 does part with a greater or less amount of 

 humidity — depending, however, no doubt, 

 on the slowness or quickness of the 

 transit. The cross section, fig. 293, of the 



Fig. 293. 



furnace, shows the fire-grate over the 

 ash-pit a. The furnace oven is surround- 

 ed by a chamber, the outer walls of which, 

 b b, are built double, to retain the heat. 

 This chamber is furnished with six rows 

 of earthenware pipes, 20 inches long, and 

 1^ inch in diameter, their orifices being 

 all kept open. As will be seen in the 

 section, these pipes are placed in a posi- 

 tion to allow the flame and smoke to pass 

 freely through the chambers, and to 

 escape at the flues / /. " The tubes, thus 

 heated, are made the channels through 

 which all the fresh air is admitted into 

 the house ; and it is easy to imagine that 

 there is a cold-air chamber externally, 

 and a warm-air chamber within, together 

 with valves and gratings to facilitate and 

 control the passage of the air, and to 

 regulate the temperature. The double 

 walls, b, are filled with pounded coke, and 

 there are air spaces, e e, all well adapted 

 to prevent the loss of heat at improper 

 places. There is also a boiler, d, with 

 steam and other pipes, to command any- 



required supply of moisture. The ends 

 of the pipes are separated by fire-bricks 

 Fig 294 cu * i n *° the form repre- 

 sented in fig. 294. The 

 apertures in the inside of 

 the house, through which 

 the warm air is admitted, 

 are as at b b. The external 

 appearance of the stoke-hole, is as below, 

 fig. 295 : u u are doors for clearing out 



Fig. 295. 



the soot ; p p flag-stones covering over the 

 air-flues ; g g the sides of the air-flues ; a 

 a space left in order to enable the furnace- 

 door to open ; and d a pipe from the 

 boiler, by means of which steam is ad- 

 mitted into the interior when necessary." — 

 Gardeners' Chronicle. We have no doubt 

 this is a powerful heating furnace ; but 

 we suspect that the humidity main- 

 tained within is derived from the fre- 

 quent use of the boiler. We also approve 

 of this furnace, in so far as earthenware 

 tubes are used, and so small a portion of 

 metallic matter is employed in its con- 

 struction. 



It may be remarked, that one of the 

 principal recommendations held out by 

 the inventors of, or advocates for, most 

 kinds of heating apparatus, is the extra- 

 ordinary economy in fuel. Mrs Tysson, 

 in a later communication to the same 

 journal, asserts that a bushel of cinders 

 per week — not more — kept her stove going 

 day and night through the winter ; — an 

 amount of fuel so exceedingly small, that 

 we apprehend this good lady either mea- 

 sures with a pretty large bushel, or has 

 intrusted the management of the dust- 

 hole to a very inefficient factor. 



A stove very similar to the last is de- 

 scribed in Ure's "Dictionary of Arts," 



