July 17, 1S0G. ] 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



45 



I need hardly Bay that I am much obliged to Mr. Radclyilo 

 (or noticing my communication, though he is rathorhard upon 

 the Jersey rosarians ; and I cannot neglect the opportunity of 

 thanking him for tho very great pleasure and profit I have 

 derived from his excollont articles on the queen of flowers. 

 " Our Journal " is certainly never moro welcomo at our firosido 

 than when "Rushton RadclylTe" is to the foro in a raid 

 among tho Roses.— One of the Jddges. 



[Thero was no misapprehension on our part, nor do wo 

 think thero was on the part of Mr. Radclyffe. As you put the 

 case now, wo could not suppose that any one fo# an instant 

 would havo a doubt. " Fifty trusses " ought not to be allowed 

 oven to bo exhibited for a prize offered for " fifty cut Roses." 

 What was intended by those who worded the schedulo is im- 

 material. " Cut Roses " mean single opened flowers, flower- 

 buds with them aro unobjectionable. The fifty-first Rose, in 

 the case, as it occurred, disqualified tho collection. — Eos.] 



DRIP AND DOUBLE-GLAZING. 

 In answer to " D. Y. S." and other inquirers : — 

 1st, There is no difficulty in explaining how a span-roofed 

 iiouse, 27 feet wide and 23 feet high, with the one end to the 

 prevailing wind, is, independently of heating, wanner than a 

 low house chiefly a lean-to, 12 feet wide and 12 feet high, as 

 the prevailing south wind would strike along the whole front 

 instead of partially on the sides, as in the other case. Again, 

 the great body of the air enclosed in the larger house renders 

 all sudden changes in the external atmosphere less perceptible. 

 This is a matter that has never received a sufficient amount of 

 attention. Without any heating, such buildings as tho large 

 conservatory at Kew, at Chatsworth, and even the huge Crystal 

 Palace, are less quickly heated and less quickly cooled than 

 smaller houses. Much has been done in maintaining a high 

 temperature in forcing-pits ; but even that was effected by 

 keeping in the heated air by covering the glass with some non- 

 conducting material at night, whenever the expense of fuel 

 was on object. Without that covering there was always danger 

 in cold nights whenever the fire went out, and that danger 

 would have been much diminished if the quantity of air en- 

 closed had been three or four times as great. The more air 

 that is enclosed under a similar plane of glass surface the more 

 regular and easily managed, as respects temperature, will be 

 the enclosed atmosphere. We can imagine that in a continued 

 frost a house 23 feet in height would come to he as cold as 

 one merely 12 feet in height, but it would be a considerable 

 time in falling so low in temperature ; and just because it is 

 ionger in cooling, so the larger building will be longer in heat- 

 ing. A large house, therefore, holds out greater inducements 

 to carelessness in air-giving and furnace-regulating than a small 

 one — a matter that should not be lost sight of by those ama- 

 teurs who must have their house for plants, and yet must he 

 away for the greater part of the day. A house containing only 

 a few feet of atmospheric air might have everything burned 

 up in it, whilst a house containing a double quantity of enclosed 

 air would suffer but little. In a house somewhat lofty, and a 

 little air given at the back early, a man may go to his business 

 in the changeable spring months with the certainty of finding 

 aU right when he returns in the afternoon. 



2nd, Protecting low houses and pits, whilst securing an 

 equable temperature, also prevents the plants suffering from 

 drip. Drip is the result of the condensation of the moisture, 

 existing in the atmosphere of the house in a state of vapour, 

 coming in contact with the cold exposed glass as a condenser. 

 The more moisture in the enclosed atmosphere, and the greater 

 the difference between the inside and the outside temperature, 

 the more will this condensation of moisture take place. Every 

 lap in the glass encourages this condensed moisture to fall all 

 over the house. In single-glazing, the plane surface of Beard's 

 plan prevents the drip falling; the moisture trickles down 

 the plane of glass and gets outside the house. Other contri- 

 vances have been adopted for taking the condensed moisture 

 down the grooved sash-bars, and then returning it to tho house 

 over the heating apparatus, so as to keep the atmosphore duly 

 moist. Perhaps the most successful mode for keeping the 

 moisturo in the atmosphere of the house and preventing alike 

 ■condensation and the consequent drip, is double-glazing the 

 roof. In all such cases the outer glazing should be moveable 

 if the inner glass should be fixed. From i to 6 inches between 

 the inner and outer planes of glass would be a suitable distance. 

 We are not so sure of the plan answering thoroughly in some 



kinds of fruit-houses, but for plant-houses it answers admir- 

 ably. Wo hope somo friends will tell where our correspondent 

 will soo tho plan in operation. On a large scalo he will see it 

 successfully practised by Mr. Bewloy, near Dublin, whoso place 

 has boon described twice at least in these pages. The moro 

 close — that is, freo from openings, the two planes of glass are, 

 the moro thoroughly will they prevent condensation and drip. 

 Tho double glass acta more perfectly in this respect than a 

 mat or a sheet thrown over a pit or frame, becauso a closely 

 enclosed body of air, whilst it does little to keep out light, 

 is one of tho best non-conductors of heat. As alluded to above 

 in tho case of forcing-houses, tho chief value of double-glazing 

 is the regularity of the temperature thus easily secured. If 

 the enclosed body of still air prevents tho lower or inside plane 

 of glass becoming cold, there can he no condensation, and no 

 consequent drip. 



3rd, Much may be done in common houses with a high tem- 

 perature and a moist atmosphere, in preventing drip even in 

 cold nights, by leaving just a little air on, especially at the 

 highest point in the roof ; tho moistest air would thus escape, 

 and a little moro firing and evaporating-pans would be wanted. 

 — R. F. 



PAMPAS GRASS— PROPAGATING GLOXINIAS 



BY THE LEAVES. 



The gardener did not cut tho Pampas Grass down early in 

 spring, and about 18 inches of the flag seems dead. If tho 

 dead part of tho flag were cut off, would the bottom green 

 part grow? It is a large bush, but has never yet flowered. 

 The gardener last winter tied it straight up a pole. Wonlo! 

 that injure it ? Can Gloxinias he propagated by their leaves ? 

 — A Subscriber. 



[After what the winter of 18G0 and 1861 did with Pampas 

 Grass, we would cut none of it down in winter or spring. 

 Every decayed part might be removed in spring, but the old 

 leaves furnish a good protection. The tying-up of the leaves' 

 would increase the protection. Give your plant plenty of 

 water and rich top-dressings now, and we hope you will have 

 plenty of flower-stems in the autumn. 



The Gloxinia propagates freely from the leaves. Tho easiest 

 way is to cut off a leaf with a good piece of the leafstalk, and 

 plant the latter in pots just as you would cuttings. The leaf 

 if thus kept in a shady moist place will soon form a tuber at 

 the base of the stalk. Another plan is to take the leaf, notch 

 it at tho back where all the smaller nervures meet the midrib, 

 fix the leaf by small pins flat on a damp surface, and small 

 tubers will form at all the notched parts. Another simple plan 

 is, to take a leaf, split it up at the midrib, and then cut outwards 

 to tho outside in strips — say one-quarter of an inch wide, 

 plant theso thickly in a pot, the part with the midrib being 

 lowest, and almost every one of these slips of leaves will form 

 a tuber at the base. It is thus easy to multiply any kind of 

 Gloxinia, or of fine-leaved Begonia, which may be propagated 

 in the same way. By these modes you do not obtain so large 

 a tuber as when you use a leaf for a single tuber instead of a 

 score or more. A moist, warm, shady place is necessary for 

 success when the leaves are thus cut up into shreds.] 



DOUBLE-GLAZING. 



TrrE very important subject of double-glazing is claiming a 

 good deal of attention just now, and deservedly so. It is not 

 our purpose to say one word about the desirability of a second 

 covering ; every gardener knows its value. To be able to main- 

 tain the proper amount of heat and moisture, with moderate 

 firing, is the point, as well as shielding us from the evils of 

 sudden depressions, which sometimes overtake us unawares. 

 Double-glazing is nothing new ; it has for many years been 

 practised in all northern continental countries for window and 

 other purposes. We aro not about to advocate tho applica- 

 tion of this principle to all garden structures — only to such as 

 are employed for early forcing, Cucumber and propagating- 

 houses, Pine and plant-stoves, &c. — in short wherever strong 

 heat is required. To these structures we think we can easily 

 prove that double-glazing would be by far the best and cheapest 

 mode. If we for a moment notice the many abortive attempts 

 that have been made, and are still being made, by anxious men to 

 cover the roofs of forcing-houses, whether by canvas, frigi domo, 

 or even " horsecloth material," and knowing, as we do, that 



