October 1, 18C8. ] 



JOURNAL OP HORTICOLTURB AND COTTAGE GAKDENEE. 



237 



WEEKLY CALENDAR. 



OCTOEKR 1-7, 1868. 



TniligM ends, lb. ZSm. after soDsct. 



Royal Horticnltaml Society, Promenade. 

 17 Sunday after Trisity. 



[and General Electing. 

 Hoyal Horticultaral Society, Fruit, Floral, 

 Ercwash VaUey Horticultural Show. 



ATcrago Temperature 

 near London. 



63.(i 

 64.7 

 64.0 

 64.1 



fia.o 



62.1 

 C8.9 



Nisht. 

 4.1.1 

 444 

 41.8 

 4:)0 

 406 

 43.3 

 441 



Mean. 

 54.4 



54 5 

 53 8 

 63.5 

 61.8 

 52.7 

 64.0 



Rain in 



last 

 41 years. 



Days. 

 21 

 19 

 14 



20 

 21 



21 

 20 



San 

 Rises. 



m. h. 

 UalC 



4 B 



n 6 



8 6 



10 6 



12 B 



13 6 



Snn 

 Sets. 



m. h. 

 8G aJ 5 



34 5 



SI r, 



29 5 



23 5 



24 5 



Moon 

 Rises. 



Moon 

 Seta. 



m. h. I m. h 

 53aJ5 i 16 at 5 



n 



G ' 21 7 

 7 1 87 8 



7 ; 45 9 



8 I 53 10 

 'J ' uoou. 



Moon'B 

 AKe. 



Days. 

 O 



18 

 17 

 18 

 19 



20 

 21 



CIoolc 



after 

 bun. 



10 i3 



10 4S 



11 7 

 11 25 



11 43 



12 

 12 17 



Day 

 o« 



Tear 



275 

 270 

 277 

 278 

 '279 

 280 

 281 



From observations taken near London during the last forty-one years, the average day temperature of the week is 63.6-; and its night 

 temperature 43.2°. The greatest heat was 80^, on the 5th, 1834 ; and the lowest cold 25', on the 5tb, 1865, The greatest fall of rain 

 was 1.06 inch. 



EARTH HEAT. 



{Contimied from page 44.) 



OLD PITS.— These structures being well 

 tnown, and extensively employed for the 

 preservation and growth of plants, any re- 

 marks upon them must necessarily possess 

 little novelty ; but considering that few im- 

 provements on pits of this description have 

 been made, and that they remain almost in 

 their original condition, I will point out what 

 I consider would tend to diminish their great, 

 and, I believe, only drawback — damp. I do not think cold 

 pits are the ideal of perfection ; indeed, I am persuaded 

 that for aftbrdiug protection to plants from the cold and 

 wet of winter, and the fluctuating heat and drought of 

 summer, they are but in their infancy. It seems strange 

 that we should employ for the summer decoration of tlie 

 flower garden plants that are in winter the better of roast- 

 ing in what is very often little less than a glass oven. 

 We are told that if lire heat hri not given in frosty periods, 

 and to dispel damp, the plants will all perish. T do not 

 consider frost need be so mucli dreaded as it is, nor that 

 it is necessary to maintain such high temperatures as are 

 often given to keep it out ; and as to damp, surely that is 

 not dissipated by putting on a lire when very commonly 

 the structure is kept closely shut up as if there were a 

 danger of frost or damp air entering. Now, for plants 

 which need no further protection in winter than from frost, 

 I look upon the erection of a place witli glass at the top, 

 ends, and sides as simply striving to build so that as much 

 artificial heat as possible will be required. Is it possible 

 to obtain warmtli by employing a material so favourable 

 as glass to the cooling of lieated air ■' Its use to twice the 

 extent that is necessary in tlie construction of houses in 

 whicli plants are required to be wintered safely, and with 

 as small an expenditure of fuel as practicable, is simply 

 waste, involving an additional first cost and a maximum 

 of annual expenditure. It is vain to seek for a lieating 

 apparatus that will afford the maximum amount of heat 

 from a minimum of fuel, so limg as we go on building our 

 greenhouses and hothouses with double the extent of glass 

 roof and sides that is requisite, employing glass in place 

 of some frost-resisting material. 



We must, however, not only seek to secure the preserva- 

 tion of plants from frost, but other conditions essential to 

 their existence. Tliese are, besides a suitable temperature, 

 light, air, and a sufliciency of moisture. Tlie first of these, 

 temperature, we have stored up for us in the eartli ; all that 

 we have to do is to prevent its escape or ward-off cold. 

 This may be effected by affording suflicient covering, but as 

 there must at times be waste, any loss of stored-up heat 

 should be made up for by catching more heat in raild periods 

 when the external is warmer than the internal atmosphere, 

 and enclosing it before it becomes cooled. As regards light, 

 erecting houses with side lights for wintering plants not 

 required to grow, but to be kept safe and in lioalth, is a 

 mistake. If plants are excited by heat, and growth takes 

 place, by all means afford light : but if they are stimulated 



No. 8M.-V0I. XV., New Sebieb. 



by artificial heat when Nature would liavo her subjects 

 at rest, the case is not then one of the preservation of 

 plants, but of forcing, and to that I intend none of my 

 remarks to apply, for 1 shall not introduce any heat beyond 

 that of the sun, and what it leaves stored-up in the earth. 

 There is, therefore, no fear of the plants being unduly 

 stimulated ; no growth will fake place but v.-hen the ex- 

 ternal temperature is equal to or above that of the pit or 

 house, and at such times the exposure of the pit will haye 

 a tendency to give increased heat, instead of reducing the 

 internal temperature, and the plants thus derive the light 

 required for healthful gi'owth. What good a powerful 

 light can do plants that are inactive I cannot comprehend. 

 Side lights, and in a measure end lights, I look upon as 

 worse than useless. ..\11 the liglit we require is tliat ad- 

 mitted by covering with glass in the most economical man- 

 ner the area occupied by the plants. " What, dispense 

 with side and end lights ! The plants will draw." Not at 

 all, if only artificial heat be afforded, and the plants be 

 allowed to rest. Look to your fathers in these matters, the 

 Dutch. '' And return from the very elegant and aristocratic 

 span-roofed house to the Dutch pit?" Just so, and whyV 

 Because these structures cost less, are less expensive to 

 keep up, and answer their purpose quite as well. " But 

 this is a retrograde step." Perhaps it may be, but I thin'ir 

 it a very necessary one, for of late very many have so 

 extended their taste for the massing of tender plants- 

 that, finding it such a drain on theu- resources, they are 

 glad to back out, and advance Beetroot, Scotch Kale, and 

 the like as substitutes ; which, at the risk of being tlicught 

 singular, I consider as much out of place in a flower gar- 

 den as vegetable quarters devoted to flowers are in a 

 kitchen garden. 



Air, it may be said, cannot be given plants in pits when 

 the external atmosphere is frosty, and without it there will 

 be an excess of damp. This may be the case when arti- 

 ficial heat is employed ; but in an unhealed structure there 

 is little to dread on that head, as the evaporation is ex- 

 tremely small, and what excess of moisture there is may 

 be carried off by judicious ventilation. 



-■Vs to damp, that certainly is a serious evil in pits ; but 

 why should it not bo overcome ? Great as the evil is, I 

 look upon it as an evil arising from tlie bad selection of a 

 site and from bad construction, ratlier than as an obstacle 

 to the preservation of the plants. In tlie selection of a 

 site prefer high to low ground, but if there is undulatin;- 

 gi'ound, take the southern side of a ridge ; or a sloping 

 bank will be an excellent place, particularly if it face soutli. 

 The more sheltered the situation the better, and if the soil 

 is sandy or gravelly, if water does not remain stagnant 

 within 8 feet of the surface, and there is a good fall fo;- 

 any drain that may be necessary, so far as site is concerned 

 such an one is eligible : but as there are not sites oflering all 

 these advantages in every garden, take the driest, most 

 sheltered, and most ca.sily drained. If the ground slopes, 

 it will be necessary to remove the soil at the bac'i, so as to 

 form a pit that will be of the required depth, which for 

 plants planted out or put in as cuttings in the bed ne«I 

 not exceed 16 inches in front and the same at back, but for 



No. 1M4.— Vol. XL., 0ld Series. 



