174* IMPROVEMENTS IN TttE CULTURE OF 



tertained the hope, that steam thrown into a cham- 

 ber, in the bottom of the plant pit, would act as a 

 proper substitute for bottom heat in place of tan, 

 as none of that substance was to be found nearer 

 than four miles distant, and when wanted was 

 often difficult to be procured. Other more gene- 

 ral considerations also made me desirous of procur- 

 ing some substitute, particularly the necessity of 

 repeatedly shifting the plants to renew the heat, 

 when the bark in the plant-pit gets cold : these 

 shiftings, besides the trouble, often retard, the 

 growth of the plants. Again, if the heat of the 

 fermentation of the tan rise much above ninety-six 

 degrees, (which it often does), and if the pots be 

 fully plunged in the tan at such a time, many in- 

 stances have been known of the roots of the plants 

 being burned, and some of them being destroyed 

 altogether. This, indeed, may be considered as 

 one of the principal reasons why so many are un- 

 successful in the culture of this fine fruit. With 

 the view of obviating the above difficulties, the 

 bottom of the fruiting Pine-pit was constructed 

 with a chamber below, into which steam was intro- 

 duced by means of copper and lead pipes from a 

 boiler placed in the shades behind : the top of the 

 chamber was constructed of rafters, on which were 

 placed broad grey slates, laid -on loose, without fill- 

 ing up the vacancies between them. The not 

 making them close, I afterwards found to be an 

 error ; for the moisture, from the condensation of 



