[ 364 J 



XLII. On Heating by Hot Water. By John Rogers, Jun., 

 Esq., F R.S. F.H.S. 



Read April 21, 1840. 



H aving for some time past directed my attention to the best 

 methods of heating Horticultural Buildings, I am induced to 

 think that a few observations on that subject may not be un- 

 acceptable to the Fellows of the Horticultural Society. Many and 

 various have been the expedients adopted for this purpose during 

 the last twenty years, each possessing some peculiar recom- 

 mendations, which are frequently more than counterbalanced by 

 attendant inconveniences. On the whole there appears no doubt 

 that the circulation of hot water in iron pipes is the best 

 means hitherto devised for this purpose. Its peculiar advantages 

 are the uniformity and durability of the heat so communicated, and 

 its perfect and equable distribution to all parts of the building. It is 

 moreover capable of effecting a considerable economy of fuel, but 

 on this head its advantages are not so great as is commonly sup- 

 posed, and depend much upon the construction of the apparatus. 

 Where this is well-constructed and well-managed, the saving of fuel 

 may amount to 25 per cent, over well-constructed and well-managed 

 flues ; but in a large proportion of the apparatus now in use, it will 

 be found that the consumption of fuel greatly exceeds that of com- 

 mon furnaces. 



This remark applies not merely to the earlier apparatus, where 

 the power was inadequate to the work required, but even to the 

 best constructed modern ones, and the waste of fuel arises from a 

 misunderstanding of the nature of a hot water apparatus, and from 

 an attempt to make it do that, which, if it be properly constructed, 

 it is impossible that it should do. 



