October 20 , 1881 .] JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 363 
principles of good taste for a table. I would state also that it has 
always appeared to me to be a matter of manipulative dexterity 
more than anything else—the making-up of bouquets—and in 
watching practised hands at work in Covent Garden and else¬ 
where I have noticed that, if provided with a suitable variety of 
flowers, they never paused to think what should come next, but 
simply “mixed ” the colours well and took care not to crowd the 
flowers, not forgetting to introduce the right proportion of green. 
This appeared to result in a very attractive bouquet. —Mug. 
TEMPERATURES FOR VINES. 
As you are discussing the subject of temperatures for Grapes in 
your pages just now, a portion of the enclosed letter from a gentle¬ 
man interested in horticulture, and no mean judge of Grapes, 
may be of some interest. I have not the honour of Mr. Taylor’s 
acquaintance, but I feel sure he will pardon me referring to his 
excellent practice here. My correspondent writes, “ By far the 
finest sight I saw on my journey, or perhaps will ever see again, 
was at Longleat—a house of Hamburgh Grapes and a house of 
Muscats. The Muscat house is 80 feet long, 30 feet wide, span- 
roofed, and four Vines fill it, one at each corner, and there are 
between 250 and 300 bunches on each Vine, splendidly finished, 
and averaging from 2 lbs. to 4 lbs. weight, in every respect 
perfect. The Hamburgh house is 60 by 30 span, also with four 
more Vines, equally good bunches, and colour perfect. They are 
grown on the cool system, and set in a temperature far below the 
usual figure.” Iu reference to the temperatures practised by 
Mr. Taylor it will be remembered that he some time ago stated in 
your pages that he had never attempted to “set ” his Grapes in 
a higher temperature than 55° or thereabout. Some experienced 
Grape-growers have stated that Muscats cannot be coloured per¬ 
fectly in a span-roofed house, but the vineries at Longleat afford 
a remarkable example to the contrary. —Correspondent. 
BOILERS versus WATER. 
The remarks by Mr. Ollerhead in the Journal of September 
29th are interesting for many reasons, and ought to have elicited 
a response from other horticulturists who have suffered in the 
same way ; but possibly none, or only a few, have tried any 
remedy. There are several compositions sold for removing and 
preventing incrustation on steam boilers which should answer as 
well for hoiticultural boilers, but the water when mixed with 
these preparations could not be safely used for other purposes, as 
it often is now. Soda is very largely used in these compounds, 
and a quantity of it alone mixed with the supply will prevent 
much furring, and if the boiler plates are smartly tapped with a 
hammer occasionally the thin scale as it forms will be loosened 
and fall to the bottom. This dropping of the scale, together with 
the ordinary sediment found in any water, would be no detriment 
in the Trentham Cornish, but might choke up the return inlets in 
other forms. It is said that of the other boilers “We found more 
or less corrosion in all of them.” Some explanation of the “more 
or less” might be found if particulars were given of the sizes or 
forms of boilers, the pipes they had to heat, and the degree of 
heat maintained. If all had been exactly alike it might reason¬ 
ably have been supposed that the water alone was at fault, but no 
mention is made of the pipes being furred up near to the boilers 
and containing the same hot water. Mr. Ollerhead considers the 
sort of water used more important than the sort of boiler. This 
being so, with your permission I will take up the latter question, 
and at once say that the Cornish boiler from its make is more 
likely to become furred up than other forms, though a large 
rivetted plain saddle would be about the same. The reason why 
may not seem so clear at first sight. The “chief seat of evil ” was 
“on the bolts along the sides of the fire ”—in other word*, on the 
projections where the fire was hottest and there was the least 
movement in the water. If there had been no bolts or rivets, as 
in a smooth welded boiler, the sediment would be more likely to 
fall to the bottom ; and if the greatest heat of the fire had been 
directed to some other place than the sides, there would not have 
been the ledge formed there. Wherever the fire has most power 
it should be arranged that the water is constantly changing, as 
the continual boiling of the water iu one spot causes the incrus¬ 
tation. This is one reason why this simple form of boiler is not 
good. The water is kept at constant boiling point along two- 
thirds of its length without any outlet, the actual heating of the 
pipes being carried on at a great disadvantage, enormous waste, 
and some risk by the remaining third of the boiler, as is more 
clearly shown by Mr. Ollerhead’s own statement that “ the pas¬ 
sage from the return pipes along the bottom of the boiler and up 
the end to the flow pipe was perfectly clear.” 
It will be said, “ Why, then, does it appear that Gray’s tubular 
boiler was nearly choked in the same way, as this is an entirely dif¬ 
ferent construction, in fact the reverse in principle ?” The reason 
will be the same though the application is different. The tubes 
used in all boilers of this class are so small that the water inside is 
quickly at boiling point, and the water has to pass so many corners 
or ledges of the rings, checking it in its way to the outlet, that 
the deposit is formed very quickly from these causes. The best 
boiler I will not attempt to decide on, as there arc both upright 
and horizontal forms advertised which will almost answer my 
ideal—namely, to send the water directly it is warmed into the 
flow-pipe without waiting for the whole mass of water in the 
boiler to be heated ; and to confine the fire heat entirely within 
the boiler, while exposing as much surface as possible to its direct 
action. 
The Editor remarks that “ defective circulation in boilers is no 
doubt often the result of furring;” but I would venture to say 
also that furring is more often the result of a defective circulation 
in the boiler, as the pipes themselves, even if only 2 inches iu 
diameter, do not become choked. This brings me to another 
point to be noticed in connection with very large boilers of any 
kind, as it will be found that this furring takes place more 
extensively in the large than in the small boilers, the water 
being the same. The facts stated by Mr. Ollerhead tell most 
severely against the “one boiler” system for great quantities 
of piping. Two miles of piping contain about 5000 gallons of 
water. This is an enormous quantity to heat even if it were all 
in one cistern, but when the water has to be heated in one boiler 
(or two containing 200 gallons each), and forced along 10,000 feet 
of pipes which give off heat at every foot, and which bend about 
in every direction, checking its circulation, it follows that the 
boiler must really be a boiler to keep up the heat under such 
conditions, some of the pipes, too, being probably 400 feet distant. 
If there were four smaller boilers, each heating a compact group 
of houses, there would be less need to have the water so intensely 
hot, and the circulation would be quicker, with less strain on the 
boiler, consequently less risk of a breakdown, and with a less 
consumption of fuel. There is a limit beyond which the economy 
of the one-boiler system disappears. For instance, in a 5000 feet 
power boiler there will be, as a rule, water equal to 400 feet of 
piping. For three months of the year it is wanted to heat only 
two or three hothouses with about 500 feet of piping, but to do so 
you must heat all the water in the boiler and mains amounting to 
as much more, when a separate boiler for these houses alone 
would only contain water equal to 40 feet of pipe, and a pro¬ 
portionately less quantity of fuel would be consumed. 
To sum up the real cause of the furring referred to, I take to 
be, not the mere hardness of the water, but the boiling of this 
hard water ; this boiling being almost necessary with such a 
quantity of piping, though not so injurious if the form of the 
boiler or the arrangement of its outlets encouraged a free and 
perfect circulation.—B. W. W. 
HIBISCUS SYRIACUS. 
There are numerous varieties of this species, the typical form 
being purple, and both the light and daik forms are very hand¬ 
some, but they are not nearly so useful as the white variety, 
the flowers of which would no doubt prove useful for bouquets. 
The value of this shrub cannot be over-estimated for late sum¬ 
mer and autumn flowering. It may be used with great advan¬ 
tage either as single specimens or grouped with other ever¬ 
greens. I saw it a few days ago used in both ways. A single 
specimen about 8 feet high and nearly as much in diameter laden 
with its beautiful white flowers was indeed charming, and smaller 
plants dotted amongst evergreen shrubs gave the borders quite a 
lively appearance. It is easily propagated, and when once esta¬ 
blished in a rich soil soon forms good-sized specimens. Its hardi¬ 
ness need not be doubted, for it has withstood the last two severe 
winters without being injured in the least. There is a double 
form, named Hibiscus syriacus flore-pleno, which may be grown 
for greenhouse and conservatory decoration, and plants are ex¬ 
tremely useful at this time of the year when flowers are scarce.— 
W. A. L 
VANDA TERES. 
It is very interesting to read of this Orchid as it is found 
growing in its native home, and it must be a truly beautiful sight 
to see it iu flower. Vanda teres can also be seen well flowered 
and in good condition in our hothouses in England. It need not 
be “scorched and starved under a glaring roof of glass,” as is 
remarked at page 342. This Orchid, like most of its family, has a 
