137 
THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, May 20, 1860. 
amount of nitrogen they contain. There may be cases to which 
this rule is not exactly applicable; but in many natural manures, 
an increase of nitrogen is accompanied by an increase in the 
phosphate of lime, and every other valuable manuring element. 
In the above table, for instance, the 13 88 of nitrogen in the 
guano is accompanied by 30 -10 parts of inorganic matter, of 
which 23 60 parts (or more than two-thirds) are phosphate of 
lime. 
“ If we take the per-centage of nitrogen, then, as a correct in¬ 
dication of manuring value, we shall find that one ton of ordi¬ 
nary Peruvian guano is equal to 
33) tons of farmyard dung. 22) tons of pigdung, and 
21 tons of horsedung. 11) tons of mixed human ex- 
38) tons of cowdung. crements.” 
Index Filicum.* —The seventh part of this useful work has 
just appeared, and is rendered all the more useful by being illus¬ 
trated with excellent plates of the genera—a feature which was 
not found in the preceding portions. The present part brings us 
on as far as Athyrium. 
WASTE OF HEAT IN GLASS STRUCTURES. 
Although there is an affinity of object between the Associa¬ 
tion for the Advancement of Social Science, and my remarks on 
the waste of heat; they are unconnected as to place and time, 
and the word then in the fourth hue of your notice should be 
corrected to has. 
The quotation (at page 111), is from my book, “A House for 
the Suburbs, Socially and Architecturally Sketched,” announced 
in your advertising columns ; but, perhaps, I may be allowed to 
mention here my belief, that the greatest appreciable amount of 
light may be obtained without the largest possible amount of 
glazed surface (a proposition with which I am glad to find you 
concur), and that the best mode of forming roofs on this econo¬ 
mising system (I speak not of money but of philosophic principle), 
is to divide the roof of a long plant-house into ridged compart¬ 
ments, running cast and west, and to make all the south sloping- 
sides, A a, of glass, and to convert the northern slopes, n e, into 
so many polished, or, at least, opaque reflectors, as in the 
annexed section, where the rays of light and heat, R it n, are 
shewn to enter the house, and to be reflected at similar but 
opposite angles, according to the law of optics, as soon as they 
strike some repelling surface, such as the floor or wall. I pur¬ 
pose to bring this subject more fully before the public.—Tit Oil as 
Mookis, Carlton Chambers, 12, Regent Street. 
STRAWBERRIES FOR EARLY FORCING. 
As it is a matter of great (and I may say general) interest, to 
ascertain the best Strawberry for early forcing, I am anxious to 
give your readers, and “ J. T.” in particular, all the information 
I can with respect to Mr. Kearns’ forced Strawberries. 
You may recollect that I stated that he had two sets of forced 
plants, both of which were named Sir Harry, although there was 
a difference of ten days between them as to earliness. In point 
of fruitfulness they were on a par. In habit I could see no ; 
difference between them, except that the leaves of the later variety 
were perhaps a shade the darkest. The early ones were procured 
from Mr. Niven, of Drumcondra ; who informs me, in reply to a 
query of mine, that as far as lie can recollect, he received them 
* Index Filicum : A Synopsis of the Genera, anil an enumeration of the 
Species of ferns, with Synonymes, References, &c. By Thomas Moore, 
i’.L.S. London : I’amplin. 
from Messrs. Henderson (he does not say which Messrs. H.). 
The later ones were from Messrs. E. G. Henderson. 
Mr. Kearns has just showed me a few plants of each kind in 
the open ground; the habit of growth seemingly identical, but 
the same difference exists as to earlincss. He mentioned to me 
that with respect to those procured from Messrs. E. G. Hender¬ 
son, there was an extraordinary deficiency in runners. This is 
not at all the case with the others. I should have mentioned that 
the fruit of the later kind was more of a cockscomb shape than 
that of the other. 
I have not sufficient experience to pronounce with authority 
which of these kinds is Sir Harry; but it is clear to me that for 
forcing the rarliest is the best. When the fruit is ripe out of 
doors I shall send you, sir, some; and then, perhaps, you will be 
kind enough to let us know whether the variety is Sir Harry, or 
Hooper's Seedling, or what it is; for, whatever its name may be, 
everybody should have it. 
Now, with respect to the quantity of fruit on Mr. Kearns’ 
plants. In spite of “J. T.’s” scepticism, I cannot consent to 
eat my words. I deliberately repeat, that on one plant (taken 
down for me to examine) I counted fifty berries, which I believe 
from their appearance at that time must all have come to per¬ 
fection ; and although Mr. Kearns kept no account of the number 
of berries he gathered from each pot, yet he says that the crop he 
gathered this year was quite unparallelled in his experience of 
Strawberry forcing—-and in this department he is no novice. 
For many years ho has forced Keens' Seedling, but will never 
encumber his house with it again—its day is passed. 
I never said that his Keens' Seedlings this year were a failure. 
They were very good for Keens' Seedling —as good as I ever saw 
them anywhere ; but, with the same treatment, they were not to 
be mentioned with the other varieties.— Q. Q. 
CRYSTAL PALACE EXHIBITION. 
The first Horticultural Exhibition of the season came off at the 
Crystal Palace on Saturday last, and a better day could not have 
been selected for proving the superiority of that establishment 
for such a purpose. The rain fell at intervals during the day in 
perfect torrents ; but no obstruction took place in the progress of 
the Exhibition, nor was there any obstacle to the enjoyment of 
the company that was assembled. 
The new regulations which have been made this year, by 
throwing all the classes open to nurserymen and amateurs in¬ 
discriminately, have proved a perfect success. We may say with 
safety that there was fully twice the number of plants exhibited 
on this occasion than was ever got together at any former Show 
in this country. This is exemplified in the collections of Orchids, 
of which there were no less than twenty-eight; and what is even 
more remarkable, there was a total absence of any second-rate 
collections, the whole being in every respect of first-rate description. 
The collections of stove and greenhouse plants were moro 
numerous than we have seen at former Exhibitions; but we 
cannot say that we observe any improvement in their cultivation, 
nor were there any novelties among them. 
The Azaleas were remarkably fine. A. variegata in the col¬ 
lection of Mr. Whitbread, gardener to Mr. Cole, of Dartford, 
attracted universal attention, and just as we were considering its 
vast circumference, we overheard our friend Mr. Beaton making 
a similar estimate, which was to the effect that he thought it 
might be somewhere about three-quarters of a mile! Another 
called Gem, in the collection of Mr. Carson, but certainly not Mr. 
Ivery’s Gem, was a floral pyramid, such as was never seen any¬ 
where before. Not a leaf could be seen, and you could not have 
put in the point of your finger without touching a bloom. The 
same may be said of lateritia snperl/a. 
The Pelargoniums were as good as they have always been, but 
nothing superior; and this suggests the question, whether or not 
it is possible to present this class of flowers in a more perfect 
condition than cultivators have already arrived at. The French 
spotted varieties seem to have taken a much greater hold on the 
public taste than our old sorts have done; but we cannot allow 
that these arc of foreign origin, for we recollect fourteen or fifteen 
years ago the oldest of these was exhibited under the name of 
Sanspareil, and here we encountered that same variety in more than 
one collection. There was a large collection of the Pelargonium 
seedlings, but we never trust ourselves to give an opiniou on these 
subjects so early in the season as May, for they have at that time 
been too much confined under glass to display their real merits. 
