302 
THE COTTAGE GARDENER AND COUNTRY GENTLEMAN Eebiujahy 14, 1860. 
to promote the lengthened vigorous vegetation of the trees, by 
sheltering them during inclement weather; by not reducing the 
temperature of the house suddenly; by giving liquid manure 
occasionally, and never allowing the trees to be subjected to a 
freezing temperature. It will be found, generally, that the 
forced tree that is kept longest vegetating healthily after its fruit 
is gathered will be the most vigorous next season. 
The experiments of Ilarting and Munter upon Vines grown in 
the open air, and those of Dr. Lindley upon Vines in a hothouse, 
coincide in testifying that this tree grows most during the less 
light and cooler hours of the twenty-four. Dut the hours of total 
darkness were the period when the Vine grew slowest. This, 
observes Dr. Lindley, seems to show the danger of employing a 
high night temperature, which forces such plants into growing 
fast at a time when Nature bids them repose. 
That the elevation of temperature at night docs hurt fully excite 
plants is proved by the fact, that the branch of a Vine kept at 
that period of the day in a temperature not higher than 50°, 
inhales from one-sixteenth to one-tenth less oxygen than a similar 
branch of the same Vine during the same night in a temperature 
of 75°. The exhalation of moisture and carbonic acid is pro- 
portionably increased by the higher temperature. 
The evidence of the Vine’s growth being most rapid during 
the hours of diminished light, but not of entire darkness, is 
curiously coincident with the observation of Moses, that, though 
fruit is brought forth by the sun, yet that the plant itself is put 
forth by the moon (Dent, xxxiii. 14). 
It must not be supposed, however, by the gardener that all 
plants make their greatest growths uniformly at the same period 
of the twenty-four hours, nor even that the same individual 
grows most every day during the same hours. So far is this 
from being the fact, and so irregular is every plant in the amount 
and period of its daily extension, that we think Dr. Lindley was t 
quite right when he thus summed up his report of a series of ex¬ 
periments made in the Chiswick Garden:—“ It does not appear i 
satisfactorily that the varying rates of elongation are, under the 
circumstances of the experiments now detailed, dependent, to 
any considerable extent, upon fluctuations of temperature, light, 
or moisture. On the contrary, it seems almost certain that some 
other powerful agent is in operation, the nature of which we have, 
at present, no means of ascertaining .”—(Horticultural Society's j 
Trans., 2nd Series, iii., 113.) 
The following table gives the epitome of the results of those 
experiments. The amount of growth merely gives the increase 
in length in inches and decimal parts of inches :— 
In a curvilinear-roofed Stove. Temperature 
during the day 73° ; during the night 65°. 
In the open air before a vinery 
in a sheltered situation. 
6 A. 11. 
to noon 
rt * 
o * 
li-o 
^ o 
-4-* 
• '"i 
2 £ 
Pi <M 
r-4 
CO O 
-+-> 
12 P.M. 
to 6 A.5I. 
Willow. 
11-13 
10-42 
9-71 
9-37 
Vis 
A1 o .. 
4-88 
5-04 
5-23 
4-37 
Vine. 
17-24 
17-21 
16-02 
18-13 
Passion-Flower 
13-41 
22-24 
18-20 
18-00 
Morning. 
After¬ 
noon. 
Night. 
4-81 
5-13 
3-77 
3-16 
2-12 
1-63 
2-04 
2-10 
2-34 
The period over which these experiments 
extended was from the 1st of March to the 
14th of August, 1843. 
The period over which these 
experiments extended was 
the month of July, 1844. 
(To he continued .) 
—J. 
GRAFTING- FRUIT TREES. 
Having at page 260, in “ A Chapter for the Cottager,” pro¬ 
mised to give a little advice on grafting, I hereby redeem the 
promise; not with a view of explaining anything new in that 
way, for the subject has been divested of its once mysterious 
importance, when the practitioners of a fruit nursery used to 
sharpen their knives and go after scions, and other things that 
were not wanted, immediately any passer-by curious enough to 
look at them stopped to do so. The day of monopolising secrecy 
is long gone by; and whip or tongue-grafting, cleft and crown¬ 
grafting, and the other modes, are known to every one who takes 
the trouble to inquire into them. But there is something more 
wanted to know than the mere manipulative part of the business. 
When to do it seems as important a part of the affair as how to 
do it; and I am not certain but that some of the smart young 
men who pride themselves as being very expert in this work are 
not often wrong in the season when it is done. My ideas re¬ 
specting this have altered very much in the last ten or a dozen 
years; and that not from what I have seen or heard of the 
practice of great men eminent in their calling, but from that of 
plain ordinary labourers, who do this work in Kent with as much 
success as any class of men I know. Perhaps some of them have 
as much practice, too, as some nurserymen; for many fruit¬ 
growers raise their own trees, and in a district where there are 
hundreds of acres of orchards there is plenty of that work to do. 
It is more especially to grafting cut-down trees that I would 
call attention. This I have seen done in other places in March, 
and I think old gardening books advise its being done at that 
time; but here it is more usual to do it in May, experience having 
proved it to be more successful at that season than earlier. The 
reason is obvious: The flow of sap is more vigorous; and, 
entering the scion at once and continuously, prevents that drying 
up so fatal with the cold north-east winds in the more early part 
of the spring. In Kent it is not unusual to see men grafting as 
late as the 12th of May, and very successfully: the tree, of 
course, had been headed down before, and the scions taken off 
and kept immersed half their length in damp sand. Now there 
is much more comfort in performing the operation at this time 
than in the cold withering weather we often have in March. True 
it is that, with care, some practitioners are tolerably successful at 
that early season, but there is more trouble in insuring success. 
I have seen each graft enveloped in a tuft of moss its whole 
length after being tied and clayed the usual way; and a cut-down 
Apple tree with many forked tops has an odd appearance when 
treated so. This moss is also often watered to prevent the drying 
winds of the time parching up the scion. But this is all a need¬ 
less amount of trouble, with not so good a result as waiting till 
the proper time, when the more rapid flow of sap supplies the 
scion with its proper food at once, and success is more certain. 
Crown-grafting is more suitable for late work than tongue-graft¬ 
ing ; nevertheless, the latter kind of grafting may often be done 
much later than it now is, and with quite as much success.— 
J. Hobson. 
TOP VENTILATION. 
I SEE no demur in your pages to the doctrine recently laid 
down by Mr. Rivers that top ventilation is superfluous. It may 
be so, but I should be sorry to be without it; and Mr. R. can 
hardly reconcile this idea with the description of “ the best house 
of the kind,” (referring to “ lean-to ” orchard-houses, where 
“ every alternate square next the top is framed on hinges opening 
upwards,”) given in that enticing book of his (page 12, 5th 
edition). 
From reading his own remarks I was convinced that, in a long 
“lean-to,” top ventilation was a necessity; and when building 
my house last winter I contrived and adopted the following plan, 
which, as it has answered perfectly, you may possibly think worth 
communicating to any inquirers on the subject. 
Every alternate squax - e next the top is framed (size 31 by 34) ; 
but, instead of being hinged, is pivoted just sufficiently out of the 
centre to cause the top edge of the frame to hang downwards 
when left to itself (fiy. 1). 
In this position what is genei’ally known as “ the-up-and-down- 
enst” system of ventilation lias full play ; the rarefied air escapes 
in the direction of the arrow pointing upwards, and fresh colder 
air descends in the direction of the other arrow. And in wet 
weather, or when showers may be expected, and the tempei'ature 
is still comparatively high; if the pivoted fi-amc be brought 
nearly horizontal, the bottom edge being very slightly lower than 
the top, there will still be an aperture of some three to six inches 
(vai-ying according to the angle of the roof) at each edge of the 
frame; so that ventilation still proceeds in the same manner 
