234 Foreign J^otices. 



som, and which is said to surpass even the old J?, arboreum in the rich- 

 ness and beauty of the color of its flowei's. It was probably raised 

 from seeds. The Messrs. Young have also a number of hybrid rhodo- 

 dendrons of their own production. — (Fax. Mag. Bot.) 



Neio mode of Heating by Hot Water, upon the same plan as that in- 

 vented by Mr. Hogg, described at p. 248, in Vol. II. — A new appara- 

 tus for heating by hot water is described, and illustrated with cuts, in 

 Paxton's Magazine of Botany for March. The boiler is composed of 

 a double cone of tin or copper, in shape nearly resembling a sugar loaf, 

 with the top cut off. The inner cone is the furnace, the space between 

 that and the outer form the boiler; so that a thin shell of water, 

 about one inch or an inch and a half in thickness, surrounds the fire. 

 From the top and the bottom of the boiler issue two pipes, fitted with 

 union joints; at the junction of the upper joint with the boiler is a small 

 steam-pipe, connected with a valve. The chimney is detached from 

 the furnace, fitting on to it like the lid of a pot, and moveable, to allow 

 the fuel to be introduced at the top of the furnace. The peculiarities 

 of the chimney are a circular plate of strong iron, nearly as large as 

 the opening of the furnace, suspended by three rods, over the fire, and 

 causing the flame to play against the sides of the boiler, the draft tak- 

 ing place all around it, and a deep rim of sheet iron about three inches 

 broad, in form of an inverted cone, attached, at its upper edge, to the 

 lid, but leaving a space of about one and a half inch between itself and 

 the circular plate or damper. 



The boiler is placed on a ring of iron, rather broader than the bottom 

 of the boiler, which is attached to a square frame of wrought iron, by 

 which it is fastened to the brick work. The grate rests on one or more 

 brackets, (as in the common cylinder stoves,) and is let down with a 

 hook when it is required to clear the furnace. 



The circulation of the water is on a similar plan to that generally 

 in use. It is described as follows : — " The pipe from the upper union 

 joint of the boiler enters the lower side of the cast-iron pipe, (a few 

 inches from the boiler,) and from the other extremity of the range of 

 iron pipes, a lead pipe, also from the lower side of the iron pipe, en- 

 ters the top of the reservoir. A strong cask answers the purpose of a 

 I'eservoir as well as anything, though an iron tank or close cistern of 

 very thin copper would be more durable. From the lower side of this 

 reservoir another lead pipe enters the union joint at the bottom of the 

 boiler ; at the highest point of the Avhole system of heating pipes, there 

 is fixed on the upper side of the pipe a small air-pipe, where the other 

 extremity is turned over into the supply cistern, so that any water casu- 

 ally thrown there is returned into that cistern. The supply cistern, the 

 bottom of which is not lower than the upper side of the pipe, is placed 

 over the reservoir, and communicates with it' by a small pipe entering 

 the reservoir at the bottom. The steam-valve is placed just above the 

 supply cistern, having a small basin or funnel round it, like those of the 

 escape-pipe of steam-vessel boilers, so that water thrown out, or con- 

 densed steam, may fall into the supply-cistern. This escape of water 

 or steam, however, can only take place when the water boils, which, 

 if the boiler be properly proportioned to its work, can rarely take 

 place. It is, however, a precaution which could not be safely omitted, 

 though the danger of water being thrown out, there, is best obviated by 

 loading the water with a small weight of two or three ounces, or a 

 quarter of a pound, on the square inch. The apparatus being filled 

 through the supply-cistern, the water enters the reservoir, and thence 

 fills both boiler and pipes, the air escaping from the air-pipe, until the 

 water standing in the bottom of the supply-cistern indicates that all is 

 full. The fire being then lighted, the heated water flows into the iron 



