November 12, 1885.] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
421 
houses or suitable for the successful treatment of plants injuriously 
affected by a hot and dry climate, as, for instance, cool Orchids and 
the Himalayan Rhododendrons or Ferns. 
Aspect also considerably affects span-roofs both as regards their 
light and heat. If the span or the ends of the house run east and 
west, then we get half the surface with a south aspect, through which 
the sun’s rays pass as in a lean-to with a similar angle and aspect, 
whilst the other half is facing the north, and the rays of light and 
heat are for the most part reflected. Thus we have the south side 
making the most of the sun’s rays, whilst the north is cooling or wast¬ 
ing it, and the deficiency of sun heat has to be made up by artificial 
means ; in fact, the economising of heat being the object, we lose 
fully one-third more of the sun’s heat by having a span running east 
and west than would be the case were the same space covered with a 
lean-to facing due south. If we reverse the position and have the 
ends of the span north and south, then we secure sun heat during the 
best part of the day. The sun’s rays are nearly as powerful at 9 a.m. 
as at noon, and there is no diminution of the sun’s influence until 
after 3 p.m. By a span we avoid the scorching noon-day rays and 
secure a greater uniformity of light and heat ; nevertheless, we lose 
much more light and heat than if we had the house of one uniform slope 
to the south, and in consequence more fire heat is necessary for the 
span-roof house than for the lean-to. I am fully aware that we do not 
employ more heating surface for a span than a lean-to, but we must 
bear in mind that, although the superficial area of glass required to 
cover a certain area with a span-roof is precisely the same as when 
the roof is a lean-to, the angle being identical, yet the height of the 
span-roof is only half that of the lean-to, and the space is lessened in 
the span proportionately. It takes less artificial heat for a lean-to 
than a span, the latter being less influenced by solar heat, which can 
only act upon one side at once. Although we lose heat in span-roofs, 
the roof being lower or more uniform than in the lean-to, they are 
very suitable for plants, as light being admitted on both sides 
equality of growth is more easily maintained, and there is also a 
further advantage in the span-roof—viz., the heat does not accumu¬ 
late so much in the upper part as would be the case were one slope 
continued so as to form a lean-to. This latter consideration appears 
the only advantage sought in unequal span-roofed houses, and I take 
it as a decided one, especially over the lean to, in preventing the 
accumulation of heat at the upper part, and when they have the 
longest slope to the south they are more economical as regards fuel 
than an equal span in the same position, owing to there being less 
glass or cooling surface exposed to the north ; hence I consider them 
very suitable for fruit houses against south walls. 
The aspect of ridge-and-furrow roofs is exactly the same re¬ 
latively as those of span-roofs, and they are employed mainly in 
covering a large area to diminish the height of the roof, for were the 
area covered by one span or a single slope the height of the ridge 
of the span or the back wall must be considerable and ill-suited to 
the growth of dwarf or even moderate-sized plants. In regard to 
light and heat, there is a great difference between the ridge-and- 
furrow and one with a single slope, for though there is the same 
surface of glass, both being placed at the same angle, yet when the 
sun’s rays are perpendicular to one side of the ridge few of them 
have any effect on the other side ; whereas, in a roof with a single 
slope the whole of the surface is exposed to the sun, and twice the 
quantity of its light and heat is transmitted into the interior. The 
ridge-and-furrow, therefore, is heated as much by the sun as a span- 
roof, but very much less than by a slope, uniform to any aspect. I 
therefore dismiss the span and ridge-and-furrow with the observation 
that they are most suitable for plants where less intensity of solar 
heat is required, and where uniformity in growth is desired from 
an equal diffusion of light, also for fruits not wanted ripe until mid¬ 
summer. 
It only remains to consider the aspect of curvilinear roofs, which 
are similar to those of spans in general principles. If the ends are 
east and west only one side is having the sun’s rays transmitted into 
it whilst the other is giving it off, and if the ends are north and south 
the same observations apply as to the span. But iu a curvilinear roof 
we have the glass placed at such an angle that more light and heat is 
admitted, as the angle is more suited to the sun’s elevation at 
different and all times of the day ; hence, curved roofs admit more 
light than those which are straight. It must, however, be borne in 
mind that curved lines, if they admit more light and heat, transmit 
heat more rapidly from the interior, as the radiation is greater from 
the larger surface of glass than in straight-roofed houses. The angle 
of a curvilinear roof is, if I may use the expression, ought to be that 
of 45°—viz., the height of the back wall or to the ridge of a span 
should be that of the width, cutting off one-third from the width, so 
as to cut off the upper or flat part of the roof ; so that if the house is 
wanted 24 feet wide and a span, the arc is described from 18 feet, 
and the width drawn in to 12 feet, half the width of the span, and we 
then get rid of the flat part of the roof, which is too fla* on the full 
curve to carry off the rain and drip. Such a house as a lean-to of half 
the width would be admirable for the forcing of fruits, and the span 
for a like purpose with the ends north and south when the fruit is 
required to ripen after midsummer, whilst for growing specimen 
plants, which ought to have light to their base, there is none better.— 
G. Abbey. 
ON LIFTING ROSES. 
I AM of opinion that Roses are often allowed to remain too long in 
the same position, and am equally satisfied that even when the same 
spot is devoted year after year to their cultivation mu’.h advantage is to 
be derived from careful lifting and replanting, especially in cold ungenial 
districts, where the soil is naturally poor. Last autumn I determined to 
lift a bed of border Carnations and plant Roses in their place. The Roses 
I selected for the purpose had been growing iu a bed for two years, which 
I determined to appropriate to the Carnations. After lifting the Carna¬ 
tions I had the bed well dug and enriched with manure and fresh soil. 1 
then dug up the Roses carefully, shortened the longer roots, and replanted 
them without a moment’s delay, with the result that every plant has done 
well, blooming better than those which were not lifted, and producing 
sturdier, shorter growth. 
The lifting gives a slight check, which is, I am satisfied, beneficial to 
the health of the plants, and affords an opportunity for renovating the 
beds with fresh materials. It has also other advantages : it insures the 
better ripening of the wood, gives a longer period of rest, and retards the 
starting of growth in spring in an appreciable and beneficial degree. 
Every rosarian will recognise these advantages on consideration of their 
likely effects on his Rose trees. 
Roses left too long in one place, especially when the soil is properly 
enriched with manure every year, are apt to giow too vigorously and to 
get overcrowded with non-productive shoots. My experience certainly is 
that the blooms on such long-standing trees, though more numerous than 
on newly planted trees, are distinctly inferior to them in size and finish. 
My advice is to replant some of the beds annually, and never to allow the 
trees to remain without lifting for more than two years. The roots will 
then be kept closer at home, and masses of fibre will be produced instead 
of long whip-like roots straggling all over the bed. I should perhaps 
add that I am writing about dwarf Roses (not standards), and particularly 
about Roses on their own roots. Perhaps I should add I am writing 
from a cold exposed situation, soil light, in the midland counties.— 
B. W. E. 
NOTES ON CHRYSANTHEMUMS. 
This has not been one of the best seasons for the well-doing of this 
autumn favourite, at all events here in Co. Meath. In the first instance 
we had frost far into the month of June, which injured the points ; in fact 
they did very little from the middle of May until cut down or stopped 
about the middle of June. From this time they began to do well until 
the first week in September, when a continuation of strong winds from 
the west threatened to finish them. Through this I lost Mr. Brunlees, 
Refulgence, Beethoven of incurved, and Madame C. Audiguier, which I 
consider one of the very best of the Japanese varieties, at least of its 
colour it has no equal. Beside others I shall miss these varieties ; however 
I have a very good supply lefr, looking very promising, the Queens 
especially, besides Prince Alfred, Lord Wolseley, Mr. Bunn, White 
Beverley, Lady Hardinge, Mrs. W. Shipman, White Globe, Jardin des 
Plantes, Princess Beatrice, and John Salter. Of Japanese, Hiver Fleuri, 
M. Delaux, Madame Bertie Kendatler, Colibri, Red Dragon, Chinaman, 
Thunberg, Comte de Germiny, Rosa Bonheur, Dr. Macary, Baronne 
de Prailly, and Comtesse de Beauregarde amongst others are very 
promising. 
Your able correspondent Mr. Orchard has some remarks respecting 
earwigs (page 561), but I consider the best guard against this pest is to 
give the plants a good shake, which will bring them to the ground, 
when they may be easily captured. This should be repeated every 
evening at sunset. When housing be sure that every decayed leaf, or any 
that may be mildewed, be removed. The decayed foliage when dry makes 
a comfortable home for the earwig. 
Another pest I consider as bad, or worse, is the cricket. I have seen 
flowers destroyed in one night by this. A very good trap is to get some 
white arsenic, say half an ounce in powder, also a quarter of a pound of 
lard ; mix the arsenic thoroughly with an old knife. When mixed wash 
some pieces of slate or broken pots, and spread some of the mixture on 
them, placing them in or near their habitation will soon destroy them ; a 
little sugar is sometimes mixed with it. 
Judging Chrysanthemums at some of the shows is no easy task, espe¬ 
cially in the cut-flower classes, where there is strong competition. 
Dublin is the only exhibition within my reach, and unless better than 
last it will not be of much account, neither was the judging deserving of 
praise. When we see reflexed flowers on a board of twency-four incurved 
flowers, and this obtaining first prize, also Japanese flowers bearing the 
name of Large Anemone flowers, I consider it is time there was an 
alteration.—J. Pithers. 
THOUGHTS ON CURRENT TOPICS. 
Judging from two or three pages of matter in the Journal last week 
the Chrysanthemum fever appears to be nearly at its height. There is 
not much wonder at the enthusiasm which is displayed in Chrysanthe' 
