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LXXXVIII. Suggestions for the Improvement of Sir George 

 Stuart Mackenzie's Plan for Forcing-houses. By 

 Thomas Andrew Knight, Esq. F. R. S. $c. President. 



Read April 4, 1817. 



Th e suggestions, for which this Society was last year in- 

 debted to Sir George Stuart Mackenzie * relative to the 

 most eligible manner of constructing forcing-houses, ap- 

 peared to me, at first view, to be extremely interesting, 

 though I immediately saw some defects in the plan sub- 

 mitted to our inspection ; and I was not without apprehen- 

 sion, that considerable difficulties would occur in obviating 

 those defects, without deviating from the spherical to the 

 spheroidal form, which Sir George Stuart Mackenzie 

 justly states to be objectionable, on account of the great 

 nicety requisite in the workmanship. On making a few 

 trials, to ascertain the varieties of forms which might be given 

 to forcing-houses, by taking different segments of a sphere, 

 I, however, soon became perfectly satisfied, that forcing- 

 houses of excellent forms, for almost every purpose, and of 

 any convenient extent, might be constructed without de- 

 viating from the spherical form; and I am now perfectly 

 confident, that such houses will be erected, and kept in re- 

 pair, at less expense, will possess the most important ad- 

 vantage of admitting greatly more light, and will be found 

 much more durable, than such as are constructed according 

 to any of the forms, which have been hitherto recommended. 



* See page 171, of this volume. 



