August 26, 1886. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
175 
Principles upon wiiicu tiie Mains can be Ap.p.anged. —There 
are at least three methods, the first being to allow the pipes to rise 
gradually from the boiler to their extreme limit ; the second is to 
convey them horizontally ; and the third to allow them to decline the 
whole distance they extend. To carry out the first satisfactorily the 
boiler must be arranged on the lowest ground, and perhaps then but 
little excavating would be needed for the stokehole ; but this depends 
entirely upon the boiler employed. If the ground was level or nearly 
so it would be immaterial at which end of the work the boiler was 
arranged ; to carry out the second plan, the lowest ground or a 
central position would be the best ; but if very unlevel this system 
should not be practisid. The third—namely, allowing the pipes to 
fall the whole of the distance they have to travel, or what is known 
in the north of the country as the “ Hammond ” principle, should 
have the boiler placed on the highest ground and the water carried to 
its highest point directly it leaves the boiler. Water can be circu¬ 
lated by this method, but it is much more complicated than either of 
the other two, and those not familiar with this principle should not 
attempt to practise it. 
The Mains —The arrangement of the mains must be determined 
by the ground unless a certain system is strictly adhered to and the 
ground excavated, if unlevel, in order to carry it out. When the 
ground is perfectly level or nearly so the mains may be carried 
perfectly horizontal and all the pipes in the houses on a higher level. 
Pipes fixed on this principle will work well, and the circulation of the 
water will be as free as if the whole of them were arranged on a 
gradual rise. Not only does the water circulate freely, but consider¬ 
able labour is saved in the regulation of the valves. If the pipes 
were allowed to rise from the boiler they need not exceed 2 to 
3 inches in each 100 feet, less would do, or more could be allowed if 
the ground rose sharply to the houses. For instance, if the ground 
was of such a nature that the pipes had to rise 18 inches or 2 feet it 
would be better to fix them thus than to excavate deeply for them. 
The system at Norris Green is arranged on ground which is highest at 
the centre. The pipes in this system rise 18 inches or more in 
150 feet and then fall for nearly the same distance, thus leaving the 
mains at the extremity only 3 or 4 inches higher than they are where 
they leave the boiler. Three houses and two pits attached to the 
extreme end of the mains cost more to heat them than thirteen other 
houses on the rising ground. This does not say much for forcing hot 
water downhill. This could readily have been remedied by keeping 
the pipes well up at the commencement, say 3 inches, and then have 
excavated the chamber 1 foot or more deeper on the rising ground, 
which would have made a difference of 15 inches in the level of the 
pipes and effected a considerable saving in fuel. The system of 
arranging all the pipes on the level is a good one, but where prac 
ticable a slight rise in the pipes is certainly advisable and insures 
circulation. Deep excavations in heating by hot water should be 
avoided, as they are costly at the commencement. 
The mains if possible should always be arranged, if outside, under 
walks or in any position where they are easy to get at. When placed 
in inconvenient positions they often entail considerable labour in 
opening them out in case of a breakdown or in searching for leaks. 
These are liable to occur in the best schemes of heating, and there¬ 
fore every precaution should be taken against placing the pipes in 
places where they are not readily accessible. It is a question whether 
the mains are best under cover—that is, in the houses or arranged 
outside independently of any of the structures that may have to be 
worked from them. Some boast that all their mains are arranged 
inside, and consequently no heat is wasted. I am familiar with 
several gardens in which this plan has been followed, and the pipes 
run along cemented and other walks, in chambers, and if anything 
happens cemented walks are destroved when broken into. This is 
not the only objection to this plan, for the houses through which they 
must pass are often kept warmer in consequence than should be the 
case. This is a very serious matter in fruit and some plant houses. 
Each house should be heated independently of each other unless the 
pipes pass through a warm house and the one beyond only needs frost 
keeping out ; but under these circumstances it is much better when 
the pipes enter each structure separately, which allows of the houses 
being utilised for any purpose without interfering with the adjoining 
one. 
Size of the Mains. —The size of the mains from the boiler is one 
of importance, and upon which there exists a variety of opinions. In 
large schemes of heating, say when 8000 to 10,000 feet of 4-inch 
piping have to be heated from one or more boilers, I certiinly advise 
the use of 6-inch mains from the boiler, say for a distance of 20 feet, 
then 4-inch are large enough for the remaining distance the water 
may have to travel. If ihe arrangement is of a more limited scale 
4-inch pipes are large enough from the boiler. I am no advocate for 
small mains from the boiler to feed 4 inch pipes in any arrangement 
where say more than 400 feet of piping has to be heated from the 
boiler. I have known small systems work admirably with 2-inch 
mains from the boiler. Four-inch connections from small boilers 
would block up the flues required for draught if they came in contact 
with them. 
The Chamber for the Mains. — Its construction is another 
important item that cannot be overlooked. In many heating arrange¬ 
ments the chambers that contain the pipes are a disgrace, and 30 con¬ 
structed that they have be pulled down every time repairs are needed, 
or the pipes assist in their own ruin and destruction. Good chambers 
should be provided, or else the durability of the pipes cannot be 
ensured. The chambers for fl >w and return main pipes should not be 
less than 18 inches wide, 2 feet would be all the better, and the same 
depth. The bottom should be bricked and then grouted to prevent 
moisture being drawn from below by the heat of the pipes, lhe 
side should be of 9-inch brickwork and the top covered with flags 
laid carefully with mortar. The joints of the flags should be made 
perfectly watertight either by mortar or a little Portland cement. 
The chambers should be of such a nature that moisture from without 
can be entirely excluded. If the pipes are capable of drawing in 
moisture they corrode quickly and are destroyed in a few years. I ue 
mains in the chamber can be arranged side by side, or they can be 
placed one above the oiher. Supports are necessary to keep them in 
position ; some place them upon bricks, others upon cast iron 
support 01 , and others upon three-quarter-inch wrought iron bars, 
which are built into the brickwork as the building of the outer walls 
of the chamber proceeds. If the latter are employed with no side 
stays the pipes are invariably twisted into all shapes, lhe supports 
cast on purpose are decidedly the best with here and there a stay 
from the walls to keep the pipes in their proper place. The pipes 
must not be built in with brickwork or surrounded with mortar, fur it 
is certain to destroy them in time if they, do not break in such 
positions through expansion. When the pipes pass through brick 
walls a small cavity should be left round them, so that they have 
room to expand in all directions if necessary. 
After the mains are fitted it is a usual practice to cover them up 
as they are, but this is a great mistake. They should be coated with 
red lead and oil worked well into the pores of the iron, which will 
preserve them from corrosion for many years. . This also prevents 
the escape of heat from the mains, which is an important matter in 
the saving of fuel and the conveyance of heat to the quarter where it 
is required. The preservation of the main pipes is a matter ot viist 
importance, so also is the radiation of heat from the mains, they 
should be coated with felt or silicate cotton or some other bad con- 
ductoi that is prepared for the purpose.— Wm. Bardney. 
(To be continued.) 
GROWING FRUIT FOR MARKET. 
EABLY PEABS. 
Coming in just after bush fruit is over early Pears aie par¬ 
ticularly valuable. They command a ready sale, but as a rule 
are handicapped by foreign importations of larger kinds. 0 
will look at Green Chisels, Doyenne d’Ete, or Citron des Cannes, 
when they can have Williams’ Bon Chretien at a not materially 
higher price? It is very tantalising to have a fruit garden just 
likely to become profitable, to find the market pre-supplied with 
foreign produce. Free trade and railway rates in favour ot the 
importer may be highly satisfactory to merchants and the 
masses ; but it is enjoyed at the sacrifice of the interests ot the 
home grower. I do not wish for protection, as that is acknowledg¬ 
ing ourselves beaten in fair competition, but surely our products 
ought to be conveyed to market at a rate that would encourage 
growers to send them to our great centres of industry without 
feeling they are doing so at a great disadvanta e on freight alone 
as compared with foreigners. The railway companies do every¬ 
thing they possibly can or dare to drive the produce of the hope 
c-rower out of the market. I have no fa th in money-grubbing 
directors shielding themselves behind the shareholders and 
making promises that the matter shall be inquired into, whilst 
the produce of the Channel Isles and sunny France is being 
delivered at less cost in our centres less even than we can send 
ours from the midlands. We want a fair field and no favour. 
We want something to bring ourselves nearer and more directly 
in unison with the wants and pockets of the consumers; we 
want, in fact, to trade at home under the “ most favoured na -ion 
clause. These are matters of vital importance to an increasing 
industry, and cannot too soon have the attention ot those 
wishing to maintain our commercial and industrial supremacy. 
These matters only want looking into from a national and not 
class point of view to give impetus to cultivators m supplying 
our markets with home-grown products. The cultivator, it 
true, must advance—keep pace with the.times lhe farmer 
clings to old moss-and-lichen-covered trees in orchards, by sub¬ 
stituting instead varieties of fruit of a newer, finer, larger, and 
