BASE-BUKXING WATEE-HEATER. 79 



conservatory attached to a dwelling or otherwise, exactly 

 as our larger boilers do, which are not usually made on 

 the base-burning principle. The patterns they have thus 

 far made (*hown in figure 22 and in section in figure 23) are 

 42 inches high and 21 inches at base, and are powerful 

 enough to heat a green-house 10 feet wide by 20 feet long, 

 or about 400 square feet of glass surface, taking into 

 account the front and ends. The complete cost of heating, 

 including boiler, pipes, and fitting up, will range from 

 $150 to $200. The care necessary in the management of 

 this base-burning water-heater is exactly the same as that 

 required for an ordinary base-burning stove, and it may 

 be safely left twelve hours without attention, keeping a 

 temperature in the house of from 50 to 60 at night, 

 which is about what is required for a general collection of 

 plants. Figure 24 shows the boiler placed alongside the 

 kitchen range, being in a basement and one story lower 

 than the conservatory. It can either be used' in this 

 way, or placed in the conservatory itself if so desired. 

 It must be borne in mind though, in constructing a con- 

 servatory, that it must be placed where a chimney can be 

 used, as of course an outlet must be had for smoke ex- 

 actly as in any ordinary room where a stove of any kind 

 is used. 



CHAPTER XIV. 



PROPAGATION OF PLANTS BY SEEDS. 



The propagation of plants of all kinds by seeds is a 

 matter in which instructions can be given only to a certain 

 extent. Long experience only can give the necessary 

 knowledge for the full understanding of the proper tern- 



