EFFECTS OF SHELTER ON CLTMATE. 



" HoRTicuLTuuE differs from Agriculture in one very ma- 

 terial respect. The latter has for its object the fertilization 

 of the soil by manures, and the different processes of culti- 

 vation in the manner best adapted to the peculiarities of 

 any given climate ; it concerns itself only with the growth 

 and nourishment of such plants as are indigenous, or, by a 

 long course of treatment, have become inured to the vicissi- 

 tudes of weather incidental to a particular latitude. The 

 former occupies a much wider field of research ; it not only 

 seeks to be conversant with the constitution of soils, but, as 

 it aspires to the promotion and propagation of exotic vegeta^ 

 tion it necessarily embraces the consideration of varieties of 

 climate ; and it labors, by art, to assimilate the confined 

 space of its operations to constitutions of atmosphere which is 

 most congenial to its change, or to protect them at different 

 periods of their growth from sudden changes of weather 

 which would be detrimental to their health. Experience has 

 anticipated theoretical knowledge in suggesting various arti- 

 fices by which these ends may be effected ; a connected view 

 of which, I believe, has never been attempted ; but may prove 

 to be not without interest and utility. The suggestions of 

 experience may probably enlarge the conclusions of theory, 

 while it is not impossible that the improved state of the 

 latter may be found to furnish some assistance to the former. 



"The season of horticulture, with regard to climate, will be 

 best considered in two divisions ; the first comprises the 

 method of mitigating the extremes, or exalting the energies; 

 of the natural climate in the open air ; the second embraces 

 the more difficult means of composing and maintaining a 

 confined atmosphere whose properties may assimilate with 

 those of the natural atmosphere in intertropical latitudes. I 

 shall commence my observations with the former. 



'' The basis of the atmosphere has been proved to be of the 



VOL. XXI. NO. XI. 63 



