PROCEEDINGS. 



built in the end wall with as much of the dome inside as possible, 

 leaving an opening outside (to which a door is affixed) for intro- 

 ducing the gas-burner which is to heat the apparatus. It was 

 stated that if it is possible (which Mr. Cuthill is confident it is) 

 to render the joints sufficiently tight to prevent leakage, this 

 invention might be found useful, near places having gas laid on, 

 in heating window gardens and small houses, which it is very 

 difficult otherwise to warm without over-heating. Mr. Cuthill 

 stated that a contrivance of this description, in a greenhouse twelve 

 feet by eight feet, has been found to work satisfactorily with a 

 gentleman in the Old Kent Road, and that a heat of 45° could be 

 maintained with ease when there were 12° of frost outside. With 

 reference to the joints of the pipes, Mr. Hood, of Iron Wharf, 

 Blackfriars, says : — " I consider they will be perfectly secure 

 when a little red and white lead are put into the socket, and that 

 no leakage of gas can occur. As soon as ever the pipes become 

 warm, the gases inside them are more rarified than the external 

 air ; consequently the pressure will be inwards and not outwards 

 — the air trying to get in and not the gas to get out. I think, 

 therefore, no disagreeable results are likely to occur from the 

 escape of gas through the joints of the pipes. As regards the 

 thickness of the pipes, I do not see that any improvement can be 

 made. If thin sheet-iron pipes were used they would soon be 

 destroyed, as the products of the combustion of carburetted 

 hydrogen gas act very rapidly on wrought-iron, so much so, that 

 a sheet-iron pipe would not last many months. The loss of heat 

 through a cast-iron pipe of the thickness of those used with the 

 gas-stove is almost or quite inappreciable ; and, therefore, even if 

 the question of durability did not arise, there would be no advan- 

 tage whatever in using thin sheet-iron pipes for the purpose." 



IV.— ARTICLES FROM THE SOCIETY'S GARDEN. 



Acacia ixiophylla and linifolia, PJiynchospermum jasminoides 

 (frost-bitten on its way to the Meeting in a covered van, the 

 thermometer on the night previous indicating no less than 14°), 

 Corraea Goodii, three varieties of Epacris, Echeveria rosea and 

 retusa, three Camellias, cut flowers of Luculia gratissima, which 

 has blossomed beautifully in the great conservatory ; a good 

 example of Cardoon (Cardon de Tours) and Lettuces : Laitue 

 chou de Naples, from the south slope of a ridge, and Iiomaiuc 

 vert d'Hiver, both excellent sorts for winter cultivation. 



