46 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ January 29, 1887. 
size of the boiler in which the fire bars have lasted for four years. To 
arrive at a true estimate of the lasting properties of the bars over hot 
vapour we must know how many feet of 4-inch piping the boiler is 
capable of heating, and the number of feet actually attached to it. TheD, 
again, it is important that we should know the temperature of the houses 
that are heated by this particular boiler, or the special purposes for which 
they are used ; then we shall be able to form a reliable opimon of the 
intensity of the heat to which the fire bars have been subjected during 
the time they have been in use, the size of the bar being also im¬ 
portant. 
. On page 540, last vol., Mr. Burton proves nothing in reference to 
oxidation by his illustration of polished iron, steel, or a new horseshoe. 
But he confirms, in a very marked degree, the repulsion between iron and 
water that I pointed out in your issue for December 9th, page 526. Red- 
hot iron repels water completely. This repulsion has been proved to 
exist, and therefore his heated piece of metal, dipped in water and re¬ 
turned to the fire, is not affected. I maintain that after the process of 
dipping in water this piece of iron will not rust if it is kept in a certain 
temperature, and the air surrounding it is perfectly dry ; but if stood in 
a corner and allowed to become cooler than the atmosphere it will con¬ 
dense moisture, and thus oxidation will take place. Tbis is the reason 
one rusts and the other does not. But inactivity and exposure will not 
result in the destruction of cast iron half so quickly as can be accom¬ 
plished when in daily use. Take a cast-iron 4-inch pipe, perfectly new, 
and lay it outside, place mains in a trench well built, and keep them hot 
day and night, but allow the pipes to draw moisture in the form of 
vapour from a tank or other source, and oxidation will be most rapid : 
thus they will be rusted in one-third the time the one exposed to the 
atmosphere. 
hatever may be urged in favour of watertight ashpits and the pre- 
servation of the bars by the vapour, or the reverse, the fact still remains 
that tubular water bars are in the end the cheapest and most durable. 
They can be fixed to most boilers, especially the saddle and its improved 
forms, and if they are what they should be when erected they will last as 
long as the boiler. They also add enormously to the power of the boiler. 
I hose who had the pleasure of seeing the hollow bars working separately 
in Sefton Park only a few years ago will know what they are capable of 
domg. It I remember rightly “ Thinker ” alluded to them in his notes 
some tune ago; if so, and he saw them, he can bear out what I say. 
Another advantage is, that any material can he burnt on these bars, for 
they are so arranged much wider apart than ordinary bars, that a large 
volume of air can be admitted to aid combustion. This reminds me of 
Mr. Stephen Castle’s notes, which I was pleased to see, and in which 
there is more than appears in a casual glance. Not only does he keep 
the bars cool by the greater distance between them, but he insures more 
perfect combusion. 
An artificial blast of either hot or cold air applied to our furnaces is 
impractical) e. It is well known that a blast of hot air is used with immense 
advantage in the smelting of iron and other similar industries. For 
urnaces m use in gardens air can only be admitted by a natural process, 
and T reel convinced that in many instances not half sufficient is admitted 
to aid or insure perfect combustion. This is largely borne out by the 
iremarks of “ Albion,” page 387, which have been previously overlooked. 
His fuel would not burn, and now that he has achieved that end he lays 
the whole credit to the vapour that rises from the water in his ashpits. 
Me has now the exact quantity of oxygen to insure combustion, and even 
less is required, since he burns a mixture of coke and anthracite, than 
would be needed to insure perfect combustion when the last was used 
alone. I maintain that the same end would have been accomplished if 
more air had been admitted to the furnace, it w®uld have supplied the 
requisite quantity of oxygen. 
I have tried anthracite for fuel, and found it very difficult to burn, for 
when fresh supplies were thrown on to a hot fire it broke into small par¬ 
ticles owing to its slow conducting power. This quickly stops the 
ra ? i ,°i r J rCTe ? t8 tbe entrance °f sufficient air to insure combustion ; 
no doubt this is the secret of “ Albion’s ” failure. To prevent this, vapour 
ot water has been recommended, but from experiments tried in America 
this process results in corrosion, due to the presence of muriate and 
sulphate of ammonia. It would be interesting to know if this is the case 
with all kmds of anthrawte coal, or whether the same effect takes place 
when other kinds of coal are burned with the aid of moisture. Hood 
states that the activity of these salts are increased by moisture, and that 
he found coke burned with moisture also produced the same results. This 
is an important matter that must he duly considered in estimating the 
value of vapour in aiding combustion ; for although a double supply of 
o ygen is afforded by its agency, and therefore less air is required to in- 
sure combustion, if corrosion results with certain kinds of fuel,"or those 
° jrora certam localities, then the vapour process as a’ general 
principle falls to the ground. 6 
.. a P ro ’? Ie ® that y°. ur , scientific readers are perhaps able to solve ; 
it will at least do for “ Thinker ” to think about When 1 asked his 
an'oninffinh 11 ^ ^ V ' ^ water an ea9 y wa y was selected of passing 
an opimon by agreeing with somebody else. But he differed, neverthe¬ 
less, inasmuch as he preferred the hot rather than the cold water. If the 
a „ an 1 t ^! 8 of hot japour were so great without corresponding disadvan- 
o/ms 1 sin^in’t rP f ri8ed tbat th u system has not become more general instead 
of passing into furnaces such enormous quantities of air-hot or cold, as 
the case may be— by artificial means. There can be no doubt that a blast 
rfn^lt Ir r ddS “ at * na,1 y ‘be intensity of the fire and increases the 
[ ap , d t ,y of combustion. When t is considered that the air must at the 
least attain the boiling point of mercury before it supports combustion, 
and by others considered to be 800° or 900° Fahr., it will readily he per¬ 
ceived that a blast of hot air would prove more beneficial than one of cold, 
for by the blast it would lower the temperature of the solid matter of the 
fuel and its gaseous products in being heated. 
If I read rightly, Mr. Burton conveys the idea that a great saving in 
fuel results from a blast of hot air, and therefore a strong point in favour 
of hot vapour from watertight ashpits. As a b'ast of hot air cannot be 
used in gardens, I shall dispense with it, for a very similar diff.-rence 
would result from the burning of coal and coke in an ordinary furnace 
such as we have in gardens. The accuracy of the statement I do not 
question, but it may mislead some, for it lacks detail. Coal cannot be 
burnt without an enormous loss, for when good average coal is carefully 
coked the residue will produce as much heat as the original quantity of 
coal would have done. When coal is carefully made into coke there is a 
loss of 38 per cent. The loss in the burning of coal is enormous when 
62 tons of coke will produce as much heat as 100 tons of coal. Gas or 
retort coke is considered 12jf per cent, inferior to “ oven coke.” But in 
spite of this it has proved to be the cheapest fuel that I have used. I 
have tried here many kinds, and from the gas coke I can get the greatest 
heat for the least money. It will thus be seen that, independent of the 
blast of hot air, that much of the difference in Mr. Burton’s figures 
between coal and coke is due to the great loss that takes place in the 
burning of coal. It appears to me to be impossible to burn coal in our 
garden furnaces without a very great loss ; in fact our methods of com¬ 
bustion are far from perfect, not only in gardens, but I think I am within 
the mark when I say in all cases in which coal is used for fuel. 
It seems to be claimed that less draught is required in the chimney 
by the aid of the vapour than would be required without it. No hard- 
and-fast line in this matter can be laid down, for the regulation of the 
damper in the chimney must be guided largely by the material that is 
used for fuel. For instance, supposing small coal was used in one case 
(this is very general) and gas or oven-coke in another, would not the first 
need greater attention, more draught in the chimney, and more air 
admitted through the fire bars than would be required to insure combus¬ 
tion in the latter, the vapour being used in both instances ? Again, with 
many flued saddles-a damper in the chimney is unnecessary, the draught 
being entirely regulated by the ashpit and furnace doors. In burning 
many kinds of fuel air must be passed over the material as well as 
under it by the ashpit if waste is to be prevented as much as possible, 
and thorough combustion insured. At the same time I do not believe in 
admitting cold air to strike directly upon the boiler, and thus lower its 
temperature.—W m. BARDNEY. 
P.S.—The above was written before the Journal appeared in which 
“ Thinker” places a construction on the sentence to which he takes ex¬ 
ception that was never intended. What I mean is, that I shall not go to 
the labour and expense of making the ashpits here watertight until the 
advocates of this system prove more conclusively than they have yet done 
that the preservation of the bars are insured by their hot vapour system. 
Some trouble has beeD taken to prove that it aids combustion, which I 
have not disputed ; but there are disadvantages even in this, and it is 
questionable whether the advantages are greater than the evils that may 
result therefrom. When the arguments are sufficiently strong to prove 
that the bars are preserved by hot vapour, then I will construct one of 
my ashpits to hold water, and test the matter by the side of thin bars 
such as has been described. They will also be put further apart to admit 
more air, by which means they can be kept cool. At present I have 
more faith in the last than the hot vapour system. If I am not mistaken, 
where blasts of hot air are employed some care is taken to prevent the 
air from imbibing moisture. I will just ask “ Thinker ” to tell us why 
a fire burns more brightly on a cold or a f roBty night than it does on a 
dull, damp, or foggy night ? We may then move a step further in the 
vapour theory.—W. B. 
MAIZE AND PHYLLOXERA. 
It is announced from Austria—and what a fortunate chance if it 
should be true—that means have been found, at once economical and sure 
of combating the phylloxera with success. Three large Vine-growers of 
that country, in whose vineyards the phylloxera had commenced its 
ravages, remarked that some Vines near which some Maize had been 
planted had not been visited by the dreaded pest, although a little further 
away some exactly similar Vines, growing in the same ground, perished 
rapidly. The idea in consequence occurred to them to plant some Maize 
in the contaminated portions, which was done, with the excellent result 
that the phylloxera abandoned the neighbouring Vines. This fact is ex¬ 
plained, it appears, not by the disappearance of the offensive insect, but 
by the marked preference which it accords to the Maize, owing to the 
substance of the latter being more tender. The Maize, then, is an expiatory 
victim, being eaten instead of the Vme. The means indicated are, it is said, 
to be applied to all parts of Croatia, a region where the Maize grows well, 
and where the phylloxera is very destructive. It would seem that the 
plan is worth trying by Vine-growers in all countries where the Ma'ze 
will grow .—(Le Courrier de VEurope.) 
RYTON MUSCAT AND GENERAL DE LA MARMORA 
GRAPES. 
The Ryton Muscat was given to my father many years since by Mr. 
Devenish of Weymouth, an amateur Grape-grower of great skill and 
experience. The gift was accompanied by the remark, “ Mr. Rivers 
