INTRODUCTION. XVII 



the fern will live, thrive, and probably seed, the seed 

 also vegetating, and at last the jar will become too 

 small for its contents ; no watering is needed, the 

 moisture in the earth will exhale, condense on the 

 glass, trickle down its sides, and so return to the 

 earth whence it arose. 



There is no limit to the application of this principle : 

 instead of a jar, it is easy to construct in the window- 

 sill, a box, extending throughout its entire length, the 

 bottom and sides being lined with zinc, to prevent the 

 moisture from damaging the adjoining wood work; 

 then let the window be a double one, like those in 

 Russia, leaving a space of six or twelve inches be- 

 tween the inner and outer glass. The ferns so 

 planted in the box, which should contain a depth of 

 five or six inches of light sandy earth, will soon fill 

 up the space between the two windows, supplying the 

 most beautiful curtain or blind that could possibly be 

 invented. The plants need not be ferns exclusively, 

 roses, fnschias, &c. would also thrive ; but it must 

 always be borne in mind, that plants requiring a 

 humid atmosphere should not be inclosed with those 

 which prefer aridity : of course the upper sash alone 

 must be made moveable. Extending the plan still 

 farther, a large conservatory may be constructed, or 

 even a large garden, entirely inclosed with glass ; all 

 the doors should be fitted with great nicety and 

 exactness, and would be better if double, and always 

 one of them shut before the second is opened. 



Houses on a large scale can scarcely be made 



c 



