428 Atkinson's prior Application of hot Water proved. 



of hot water; and in 1822, shortly before I left him, he had 

 a tin model made, consisting of two cubical boxes (with 

 covers) *, connected by two small pipes, one pipe near the tops, 

 the other near the bottoms, of the boxes. I assisted him to 

 make the first trial of this apparatus, and was the only person 

 present with him when it was made. He succeeded very soon 

 in producing a current, and in heating the water in the vessel 

 most distant from the fire. We differed in opinion at the 

 time, respecting the precautions it would require in practice : 

 it was my opinion that either a tube of safety or a safety valve 

 would be necessary, as I conceived it quite possible that the 

 whole of the water might be raised above the boiling point. 

 How far this is possible or impossible would, however, not be 

 necessary to enquire, if the attention of the gardener to the 

 fire could be entirely depended on. 



Mr. Bacon was not known to Mr. Atkinson at that time, 

 and, now that his house is warmed by hot water, it is of the 

 same construction as the above-described model, and it was 

 confessedly done under Mr. Atkinson's direction : hence it is 

 obvious enough that the successful application of hot water to 

 heat forcing-houses is due to Mr. Atkinson. 



The unsuccessful or uncompleted trials are of an earlier 

 date. In 1 799, Mr. R. Weston proposed to heat pine stoves 

 and beds by hot water {Repository of Arts, vol. xiii. p. 238. and 

 314., old series), and Bosc has the following passage in his 

 Art. Serre {Diet. Agricult. Ency. Meth. 1816.): — " J'ai ete 

 temoin des essais qui ont ete faits au jardin du Museum pour 

 chauffer les serres, au moyen de tuyaux de cuivre remplis 

 d'eau chaude qui se renouveloit sans cesse. On y a renonce, 

 parceque cette chaleur etoit trop egale en tout temps et 

 trop foible pour les temps de gelee." f The concluding 

 remark deserves attention. 



Mr. Knight proposed a combination of the action of steam 

 and hot water {Hort. Trans, ii. 334.), and I have partially put 

 it in practice with considerable success.:): 



I did propose to conclude these notices with a few remarks 

 on the proportions of hot water apparatus, as the knowledge 

 of an unapplied invention prevented me doing so in my work 



* We presume that described by Mr. Barrow, p. 424. fig. 164. — Cond 

 f " I witnessed some trials, made in the garden of the Museum, of 

 heating the hot-houses by means of copper pipes filled with hot water 

 incessantly renewed. But that plan was given up, because the heat was 

 found, in all weathers, too equal in degree, and too weak during frosty 

 weather." 



J The Comte Chabanne's method, as exemplified at Sundridge Park 

 (p. 190.), is a very near approach to that suggested by Mr. Knight. — Cond. 



