102 On the Cidlivatlon. of the Pelurgoniuvi. 
To the top of the boiler, I have a metal pipe two inches in diameter, 
as K, which reaches to the further side of the pine-pit, as l; at the 
side of the pipe, next the pit, I have two openings, to which lead pipes 
of an inch diameter are fixed very, securely, — these are placed about a 
foot from the front and back walls, and reach to the end of the pit, 
the ends are closed up. The pipes are perforated on each side, with 
holes about an eighth of an inch \\\ diameter, as at m, the holes are, at 
the commencement, (reckoning from the end next the boiler) twelve 
inches apart, diminishing half an inch from hole to hole, to the end of 
each pipe- The length of the pit inside, is 24 feet; breadth, 10 feet. 
When the steam is not wanted, it escapes as at \. 
The pipes are laid upon stones or bricks, raised a few inches from 
the bottom of the pit; but previously to placing the pipes, 1 had the 
bottom of the pit made of a considerable slope to one corner, so that 
by having a drain, I readily take away all the condensed water. The 
pit, inside, is built on what is usually termed the pigeon-hole plan, (al- 
lowing a small space between the ends of the bricks) the space being 
about an inch between every brick, this admits the steam to circu- 
late freely, thoughout the pit. 
When the pit is walled up to a few inches of its required height, I 
leave less distance in the spaces between the bricks, so that the bricks 
nearly touch at the surface; this is to prevent too great a quantity of 
steam escaping into the pit. The pit is filled so high as only to allow 
for a few inches deep of birch twigs being placed on the brick surface, 
and then as much bark or leaves as will allow the pots to be plunged 
the required depth, the quantity of materials heated in the pit being 
so great, and being confined, retains its heat for some weeks, so that 
very little trouble is required in heating the pit, and when the steam is 
turned on for heating, it only requires it for thi'ee or four hours at the 
utmost. 
I am, gentlemen. 
Yours, &c. 
July 20th, 1831. John Llster. 
Article IV. — On the Cultivation of the Pelargonium, as 
practised at the Right Honorable the Earl of Egremonfs, 
Petworth-House, Sussex. By Mr. George Harrison, 
Uiider-Gardener there. 
Gentlemen, 
With very great pleasure and interest, I have perused the 
first lumiber of your Horticultural Register, and now take up my pen 
to detail the mode of treatment 1 pursue with that beautiful genus. 
