Improved Boiler for Hot-houses. 143 



The fireplace and boiler may be safely brought into the 

 house, from which arrangement an increase of heat is ob- 

 viously acquired. I do not by any means consider it judicious 

 to employ the hot-water pipes alone, and to throw the fire 

 heat into the nearest chimney : in this case no more savins is 

 effected than if the fire-fiue were used by itself, and from my 

 experience not so much. 



My boiler {fg. 20. a) is placed in a recess at the end of the 



flue at the back 



-'^ r "^ P'^^^ ^^ ^^^^ house, 



A \ I - \ {, I so that it occa- 



*^ ■'^ 1 — I sions no inconve- 



nience whatever. 

 My feeder (^) is situated very handily at the liot-house door, 

 and communicates with the boiler by pipes (f). 



I shall here give you my opinion, as to where I think the 

 hot-water svstem mav be used with most advantage. In the 

 first place, it is excellent, jointly with a fire-flue, m all kinds 

 of forcing that require a temperature above or about 55°, 

 imless for very small pits and frames, where it may be used 

 singly, on account of the pipes takuig up little room and 

 being readily fitted in. In such places as the cjreen-house, 

 where nothing more than the frost is to be excluded, the 

 old flue system is the best ; and if it be properly managed, 

 no inconvenience will arise from disagreeable smells or 

 smoke. \\^ith regard to doing away with the fire-flue, on 

 account of the water-pipes being sweeter, and more conrjenial 

 to the health of the plants, I beg to remark that, if the fire- 

 place and flues are properly constructed and kept properly 

 clean, they are sufficiently sweet for any plant, provided 

 that a proper degree of humidity is maintained. 



I am not a little surprised that the method of heating by 

 hot air has not been introduced into hot-houses, for which 

 I think it well calculated. In my opinion the plan of Messrs. 

 Sunnners of Bond JStreet might, with a little alteration for 

 the particular purpose, be made more suitable for this object, 

 to any number of houses, than any that I have yet seen. 



Mr. Smith informs me that Mr. Oslar is now fitting up 

 a hot-air stove to heat a room. It will require compara- 

 tively a mere handful of fuel ; and is also considered suffi- 

 cient to heat a hot-house 20 ft. by 12 ft. to a temperature of 

 80°. Mr. Smith says he is going to try another plan, which, 

 he thinks, will answer the purpose of hot-houses much, better, 

 and jirove far cheaper than hot-water pipes. The room in 

 which he has tried his experiment loses but 3° of heat in 

 twelve hours. Yours, C>cc. 



Shobden Court, Nov. 1. 1829. John Mearns. 



