THE GARDENING WORLD 
134 
would have to prove carelessness or neglect 
or wilful damage on the part of the railway 
company. Despatch at the owner’s risk is 
the most popular method. 
263 2. Cause of Hot Water Circulating. 
What is The cause of hot water circulating 
in a heating apparatus, and why is the flow 
or top pipe on a ji.se to the extreme end 
of the house and then falling in the bottom 
pipe to the boiler ? (Regular Reader, Notts.) 
Hot water is in a greater state of expansion • 
than oold water, and is consequently lighter. 
Hot wafer, therefore, will always rise to 
the top and cold water sink to the bottom, - 
simply as the result of ordinary gravitation. ' 
The flow pipe is made slightly higher at 
the far end from the boiler to encourage the 
regular flow of the water. As this gets away 
from the boiler it loses its heat and again 
becomes heavy and, of course, finds it way 
by the return pipe, which is lower. You 
might have a flow and return in the same 
pipe as you would in a kettle, but it would 
not circulate so quickly or readily by having 
two opposing currents. 
2633. Temperature of House. 
What temperature should two rows of 4 in. 
pipes be able comfortably to keep up in 
winter time, day and night, that are round 
three sides of a house 19 ft. long, 16 ft. wide, 
13 ft. high at the top and 5 ft. at the front? 
It is a lean-to. (Regular Reader, Notts.) 
You have to calculate that during certain ' 
nights of the winter the temperature is liable 
to fall as low as 10 degs., that is, you would 
have 22 degs. of frost outside. It is a safe 
plan, therefore, to calculate the requirements 
of a greenhouse by the minimum temperature 
you are likely to get outside. Even by this 
means, if the pipes seem to be excessive 
under ordinary circumstances with a tem¬ 
perature slightly below or slightly above 
freezing, it would be wrong to put in pipes 
merely to maintain a temperature calculated 
on this basis. The piping you mention would , 
onlv raise the temperature to something like 
43 (legs, with a temperature at 10 degs. out- 
s.de. To maintain the temperature you would 
have to drive your boilers, and your plants-- 
would suffer owing to the .aridity of the atmo¬ 
sphere. YVe do not mean to imply that you' 
cannot get a higher temperature in that housp 
by the piping you mention, but that it would 
be difficult to get it when hard frost pre¬ 
vailed or when very cold east winds are 
blowing, while freezing is taking place at 
the same time. 
2634. Two or Three Pows of Piping. 
Do you consider that for a house iq ft. 
long. 16 ft. wide and 13 ft. high at the top 
end, 5 ft. high at the front, a lean-to, two 
rows of 4 in. pipes around the sides of the 
house and three rows of 4 in. pipes on the 
third or front side of the house sufficient 
piping to maintain an intermediate tempera¬ 
ture during the winter months? What 
should an intermediate temperature be dur¬ 
ing day and night in the winter time? 
(Regular Reader, Notts.) 
The minimum night temperature of an in¬ 
termediate house in winter should be some- - 
thing like 50 degs. It depends, of course,, 
what you actual!}' want to grow'in the house. 
1 hat temperature should be raised to pc; degs. 
during the day by artificial heat. Then, if 
the sun is shining strongly, it might even .. 
rise to 60 degs. We scarcely think you have 
sufficient piping to keep up that temperature. 
In our estimation, with the temperature out¬ 
side at 10 degs. Fah., the piping would only 
give you a temperature of 45 degs. with ease. 
1 he better plan would be to put three ¥ow.S . 
of piping round the ends as well as the front 
side of that house. That would give you 
1:3 ft. of 4 in. piping for the house, and 
if the boiler is in good working order, you 
should have- no difficulty in maintaining a 
suitable temperature even during severe 
weather, 
NAMES OF PLANTS. 
(A. Jameson) 1, Erica carnea; 2, Corpus 
Mas; 3, Lonicera fragrantissima; 4, Jas- 
minum nudiliorum. 
(T. W. W.) 1, Epiphyllum truncatum ; 2, 
Begonia weltoniensis; 3, Saxifraga sarmen- 
“ What is a leaf mould and-how shall I 
make one ?” is a- question which amused 
me a little when I received it by post. 
As there are probably,, at’ feast, some"' 
readers who have hazy ide-as about leaf 
mould, 1 will, in a few lines, describe 
What Leaf Mould is. 
Leaf mould consists of dead leaves pure 
and simple. There is, or should be, no 
admixture of soil or mould from the gar¬ 
den, nothing but the dead leaves as they 
fall from the trees and are brushed or 
raked up in autumn and winter. The 
mould, which gives the s-tuff its earthy- 
name, is formed by the decay of the 
leaves, but the best leaf mould is always' 
more flabby than powdery, so that mould 
is somewhat of a misnomer. 
Leaf mould is formed by stacking dead 
leaves in the open air and allowing them 
to lie until they rot and fall to pieces. 
A shed is not a desirable storage place, as 
wet is essential to the decay and disin¬ 
tegration of the leaves. Oak leaves make 
the best leaf mould, followed by Beech, 
Lime, and Elm. When woody leaves 
like Horsechestnut, are used, the mould 
should be sifted through a square meshed 
February 22, 1908. 
' 
tosa; 4, Gasteria verrucosa; 5, Pteris serru- - 
lata. 
(G. F. Reid) 1, Acacia Drummondii; 2, 
Acacia armata ; 3, Cyrtomium falcatum; 4, 
Scirpus oernuus (often named Isolepis. 
gracilis). 
sieve before using. One part of leaf 
mould to two parts of loam forms the 
basis of most potting soils. 
Why Rhubarb is Forced in Darkness. 
Not only is growth more rapid in dark¬ 
ness than in light, but it is found that 
Rhubarb grown in the dark and kept 
nicely moist is-better in appearance than 
and much superior in flavour to- that 
forced in the light. Hence we cover out¬ 
door Rhubarb with pots and boxes during 
forcing, and grow indoor Rhubarb in 
Mushroom houses ; or under darkened 
stages in the greenhouse. 
The Pip of a Flower. 
When pip is used in connection with 
flowers it signifies an individual blossom 
in a collection or truss. Thus, florists \ 
call the inflorescence of the Auricula and 
Zonal Pelargonium a truss, but each in¬ 
dividual flower, in the truss is called a 
pip. And pip is so used with many other 
flowers,-but always in the same sense. \ 
Pip is also used as the name of the seed 
in Apples, the latter being from this 
called Pippin fruits. 
(To be continued.) 
19 
ijrsjpnBl 1 ffij 
Address The Secretary, 
You cannot do better than consult 
our Illustrated Guide for Amateur 
Gardeners, Sprint/, 1908,16) )topp, 
190 illustrs., 2 beautifully coloured 
plates, and many cultural h ints. 
In it you will find catalogued I 
every description of Vegetable and j 
Flower Seeds, all of the finest quality, 
and at moderate prices. 
It deals also largely with Fruit I 
Trccs.Roscs, andPlants, infact with | 
Everyth ingRequ iredfor theGarden. 
Our reputation has been built up | 
on the QUALITY of the seeds and j 
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A copy will be sent to all intending j 
purchasers on receipt of 3d. to cover \ 
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DANIELS BROS. Ltd. 
By Appointment 
To H.M. The King. 
NORWICH. 
<L7 
BY AN OLD HAND. (Continued Jromp. 72). 
