268 



SCIENCE OF GARDENING. 



PART II. 



BOOK III. 



MECHANICAL AGENTS EMPLOYED IN GARDENING. 



1293. HAVING considered the nature of vegetables, and the nature of the materials by 

 which their culture or improvement is effected by art, the next step is to consider the 

 means by which art is applied in the practice of cultivation. In general it may be ob- 

 served, that every change effected in the circumstances of materials, either consists in, 

 or must be preceded by, a mechanical change in their position. To effect mechanical 

 changes, the fundamental engine is the human frame ; but its agency is essentially in- 

 creased by the use of certain implements, utensils, machines, and buildings. The 

 primary implements of gardening, as an art of culture, would necessarily be confined to 

 a few tools for stirring the ground, and one or two instruments for pruning trees or 

 gathering crops. But in the present state of the art, both the number and kind of agents 

 are greatly extended and diversified. There are tools, instruments, and machines for 

 culture, as the spade, knife, and water-engine ; for beautifying scenery, as the broom, 

 scythe, and roller ; utensils for portable habitations of plants, or conveying materials, as 

 pots and baskets ; structures for culture, as glass frames, hot-houses, and awnings ; and 

 buildings for use, convenience, or decoration, as tool-houses, arbors, and obelisks. The 

 whole may be included under implements, structures, and edifices, as in the following 

 Table : 



Edifices 



