560 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ December 24, 1885. 
The heating power of a boiler is contingent upon the surface 
exposed to the direct action of the fire and upon the water it 
contains. If we take a tube an inch in diameter we get four times 
the heat surface for the same quantity of water as if we employ a 
2-inch tube ; therefore heat four times the quantity of water, for 
as is the heat so is the circulation, or it will circulate very much 
more quickly in the small tubes than in the large. I make no 
account of indirect heat, only in that the heat is utilised in main¬ 
taining or preventing the loss of the direct. It is best utilised in 
heating, as in the Cornish Trentham, by passing under the boiler, 
and so warming the cold water before it is acted upon by the direct 
heat of the furnace. In the hollow grate bars of the Terminal 
Saddle as well as in the Tubular boilers the water is heated before 
it is acted upon by the full force of the furnace heat, but the heat 
in this case is direct, and it must be said greatly auxiliary. Except, 
therefore, in utilising indirect heat, preventing the loss of direct heat, 
or in warming surfaces wanted heated which are colder than those 
exposed to the greatest heat, its benefit is purely chimerical. 
Boilers are economical not only in construction but in the way 
the heat is utilised after it is obtained. The water should have 
free access in entering the boiler and an equally free passage out, 
but it must be understood that as soon as it leaves the boiler it is 
losing heat, and continues to do so throughout the whole extent of 
the pipes. Some have an idea that a main of large diameter is 
necessary. Now, just get a 2-inch pipe and give it a sharp incline, 
and it will carry off as much water as a pipe of double the diameter 
on nearly a dead level. This of course is due to gravity, and in 
heating by hot water we have not only gravity but the ascending 
force of heat. What reason is there to take a 6-inch or 4-inch main 
from the boiler to the house required heated when the water will 
travel much more quickly through a 2-inch, and we have only an 
eighth of the water, with half the extent of radiating or heat-losing 
surface ? These mains, whatever then’ size, are taken in flues and 
are bare, therefore losing heat the whole of their length, whereas 
were they covered with hard felt they would radiate or lose very 
little ; and when we take into consideration the loss occasioned by 
the needless large flow and return pipes, their exposure throughout 
the distance between the source of heat and the structure required 
heating to cooling influence, we' have to face a waste of power of 
a most extravagant kind, which is added to by an oversight in valves 
te shut off the heat alike from the house and boiler. How often 
do we see the valves on the pipes just inside the house, leaving it 
may be half as much piping between the house and boiler without 
means of disconnection ? The. water will not rise up the flow, still 
less the return pipe— i.e., it cannot circulate. Why, it circulates in 
a kettle, and it circulates in pipes, even in the return pipes after 
disconnection at the house up to the points of disconnection from 
the boiler, and this is all waste heat. If the mains pass through 
houses required heated, then of course these remarks lose their 
point, but in the case of detached houses they are worthy of con¬ 
sideration from an economical point of view, and the point of dis¬ 
connection ought to be at or near the boiler. I once had under 
my charge half a dozen detached houses heated from one boiler, 
and to have taken the heated water to them in full-sized or 4-inch 
mains would have required as much surface in connection as the 
houses required heating surface. More money is wasted in “ cob¬ 
bling ’’ by unskilled hands than is necessary to execute anything in 
the best manner of the best material. I had a box made, and from 
this all the flows were taken, and all were inch, and the valve 
upon each close to the box. Similar means were taken with the 
return pipes just before entering the boiler. It answered perfectly. 
The cold water had free access and the hot free passage out of the 
boiler. All the pipes ought to have valves—screw valves on the 
flows and throttle valves on return. If they are worth anything at 
all the screws will shut off to a drop, and the throttle will effectu¬ 
ally check or close the circulation Hot water will back up the 
return pipes, hence the need of valves on them. 
The next chief point is to have plenty of piping, and as a rule small 
houses require more piping proportionately than large ones do, and 
lean-to’s require less piping than span-roofs. Then houses required 
to be kept at a high temperature will bear the water or heating 
surface hotter b than those -which need only a temperate heat, as 
the latter are more susceptible of heat than the former. About 
half as much heating surface is required for a greenhouse as for a 
stove; and as a rule for calculating the heating surface needed I 
think there is none better than allowing a 4-inch flow and return 
for every 6 feet of width for securing a stove temperature for 
forced Grapes, Figs, Cucumbers, Melons, &c., whilst half that will 
suffice for a greenhouse. Height, of course, has much to do with 
it, but taking the height to be not more than the width squared, I 
find it answer very well, and is better than making no end of calcu¬ 
lation about feet of heating surface required to heat so many cubic 
feet of air the chief thing being to have too much rather than too 
little. Any extra first cost will be more than counterbalanced by 
the saving in fuel and the results obtained. 
As to the best position for the pipes I do not think we can improve 
upon having them at the front of lean-to’s or at the side of spans, 
being careful only to have them isolated, clear of the walls above 
the soil, and so that the atmosphere will not be so dried as to 
seriously affect the plants. If the pipes can be placed so as to 
diffuse the heat equally all the better, but I have tried it and find 
that the best results are obtained when they are at the lowest part of 
the house, and only in the case of wide houses are back pipes in the 
case of lean-to’s, or centre pipes in the case of spans, needed ; but in 
large houses they are wanted, so as to keep up a circulation of air 
throughout with an equality of moisture, but then the centre or 
back piping should not be more than one-half that of the front or 
side.—G. Abbey. 
(To be continued.) 
We understand that a Horticultural Congress at Paris 
will be held in conjunction with the French National Horticultural 
Society’s Show on May 4th to 9th, 1886. 
- It is announced that The Rosarian’S Year Book for 1886 
will be issued shortly, and will contain a photograph of Mr. B. R. Cant, 
together with the following articles :—“ A Symposium of Mildew” (illus¬ 
trated), “ Winning Roses,” “ The Fortunate Isles and their Roses,” “ The 
Rose, and National Rose Society in 1886,” “ Some Single Roses as Decora¬ 
tive Plants,” “Dew of the Ever-living Rose” (a review), “Climbing 
Roses,” and “ The Rose Weather of 1885.” 
-The Royal Botanical Society of Manchester have 
fixed the following dates for their Shows in 1886—Spring Show, 16th 
and 17th March, and 27th April; National Horticultural Exhibition, 
11th June and following days ; Rose Show, 17th July; Chrysanthemum 
Show, 23rd and 24th November. 
- “ T. S.” writes :—“ On reading the remarks of our friend 
“ Thinker ” on Gas tar I was reminded of a case which was related to 
me some time since, and which goes to show that it will spoil the flavour 
of less delicate productions than Peaches. Gas tar was used in the 
Potato store to drive away rats, and all the tubers placed in the vicinity 
of the tar were strongly flavoured with it.” 
- We regret to announce the death of Mr. Alexander 
Protheroe of Leytonstone, which took place on the 19th inst., in ‘he 
eighty-second year of his age. Mr. Protheroe was one of the founders, as 
he was the head, of the firm of Protheroe & Morris, the well-known 
auctioneers and nurserymen of Leytonstone. 
— — We understand that the post of Assistant Director of the 
Royal Gardens, Kew, has been offered to Mr. D. Morris, M.A., F.G.S., 
the Director of Public Gardens and Plantations, Jamaica. The appoint¬ 
ment is in the gift of the First Lord of the Treasury. 
-The annual general meeting of the Kingston Chrysanthemum 
Society was held on the 16th inst. in the Wood Street Schools, Mr. 
Lyne of Wimbledon taking the chair. The balance-sheet was read by 
the Hon. Secretary, Mr. T. Jackson, and from this it appeared that the 
total balance at the beginning of the year was £105 2s. 9d. The sub¬ 
scriptions amounted to £110 6s. 6d., and the takings at the Show to 
£92 10s. 6d. ; these with other minor items and the balance brought for¬ 
ward gave a total fund of £323 5s. 3d. The disbursements, including 
prizes, came to £212 5s. 9d., thus leaving a balance of £110 19s. 6d. The 
receipts for the year exceeded the expenditure by £5 16s. 9d., which i 
considering they had two bad days for the Show, Mr. Jackson considered 
was exceedingly satisfactory. The other business transacted by the re- 
election of Mr. F. A. Davis as President, Mr. Drewett as Hon. Treasurer, 
Mr. T. Jackson as Hon. Secretary, and the Committee as follows: — 
Messrs. Attrill, Bates, Child, Hardy, King, Lyne, Moorman, Orchard, 
Puttock, Rolt, Shepherd, Slade, and Woodgate, the new members being 
Dr. Walker and Mr. Glover. 
