February 10, 1863. ] JOUitNAL OF HOBTICUXTUBE AND COTTAGE GABDENEK. 



Ill 



B. ulmifolia. — Blush-coloured flowers. 



B. castaneafolia. — Blush-coloured flowers ; neat habit of 

 growth. 



B. semperflorens. — White flowers. 



B. euculata. — White flowers ; stems slightly tinged with 

 purple at the joints. 



B. papillosa.- — Pint flowers. 



B. digitata. — White. 



B. rubra. — A beautiful red not only in the petals but also in 

 the capsules. 



B. platanifolia. — Pink and white. 



B. heracleifolia. — Pink blossoms, low habit, and dark green 

 ivy-like leaves. 



B. Barkerii. — Immense leaves, and a large head of odoriferous 

 flowers. Increased by seed. 



B. hernandiafolia. — Rosy-red flowers. W. Keane. 



HEATING HORTICULTURAL BUILDINGS. 



Manifold as are the modes by which glass structures and 

 other places devoted to horticulture are heated, the subject is 

 certainly far from being well understood. True it is that those 

 who hare had extensive practice in heating may be able to give 

 opinions of considerable weight on the matter ; but there are 

 many who may not have obtained such experience, and, conse- 

 quently, may be led into error — not, perhaps, always in neglect- 

 ing to provide sufficiently powerful heating apparatus, but by 

 running into needless expense in providing it in a manner not 

 required. This is also a subject in which the most experienced 

 sometimes make mistakes, therefore I offer no apology for 

 making some observations upon it ; not that I have anything 

 to advance in contradiction to the able communications Mr. Pish 

 has from time to time put forth, but some additional facts bear- 

 ing on the case which, if not new to the practical men who 

 keep pace with the times, will at least be interesting to the 

 general reader. 



I believe it will be admitted by all, that the best-constructed 

 heating apparatus yet erected falls far short of supplying the 

 heat that ought to be furnished by the fuel consumed ; in 

 fact, bo extensive is the waste, that the statements of the learned 

 men who have treated on the subject seem almost startling, 

 but it is questionable whether anything even like the results 

 they assume to be possible will ever be secured in practice. 

 Nevertheless, there is every reason to believe that very consider- 

 able improvement may yet be made ; and although the com- 

 bustion of a pound of coal may never effect the wonderful 

 changes that men of science assert it ought to do, it may yet be 

 so economically used as to impart a greater portion of heat to 

 the object wanting it than it now does ; and if a mode of doing 

 this without entailing additional labour or cost can be found, 

 the discoverer will deserve well of his fellow men. 



The present notes, however, will be devoted to the application 

 of heat to such purposes of horticulture as tend to impart heat 

 to the atmosphere of a structure adapted to the cultivation of 

 plants. In thus limiting its operations, we must also fetter it 

 in another way as well. The heat supplied must not contain 

 any gases hurtful to vegetation, but must simply be a good and 

 agreeable warmth, free from any impurity ; neither must it be 

 too dry nor yet too moist ; in fact, it ought to be completely 

 under control in these last two respects, and at the same time 

 the simplicity of the apparatus must be such that any rustic 

 may be safely trusted with its management. It must, besides, 

 require no particular attention calling the operator very often 

 to it, for there may be times at which the man or boy who 

 has the charge of such works may want to be somewhere else ; 

 and if an apparatus for heating requires attention every hour 

 or two, there is every probability of this duty being often 

 neglected. 



In the cultivation of exotic plants, it is often necessary to 

 increase the temperature of the atmosphere they are placed in to 

 something like that of the country they came from ; or, at least, 

 we are obliged to prevent that atmosphere from being cooled 

 down so low as it would be in our climate. To prevent this 

 artificial heat has to be applied ; and whether this heat be in 

 the shape of fermenting material or fire heat, the object must 

 be accomplished. Other modes of heating have been suggested, 

 as making use of the heat from the sun's rays ; but we have not 

 yet found the way of concentrating the spare heat that might be 

 eo obtained, and giving it off at night, although this is far from 



being so improbable as some may suppose. Neither has a much 

 more difficult problem — that of taking advantage of animal 

 heat, which was suggested by 6ome one, been hitherto solved. 

 If I remember right he proposed to have a forcing-house, or 

 something of that kind, immediately in front of a row of cattle 

 tied-up and feeding. The warmth from their bodies and their 

 breath together, he thought might supply the heat required. 

 How such a system would suit the owners of stall-fed oxen, I 

 must leave them to say ; and how the animals themselves 

 wouM enjoy the tantalising prospect of green herbage, rich, 

 tempting, and pretty, but out of their reach I cannot aver. It 

 is almost superfluous to add that the plan has never yet worked 

 itself into practice, neither is it likely that it will be adopted 

 by any but by those anxiously bent on novelty ; for it is pro- 

 bable the improved modes of using fire heat will drive all others 

 out of the field. I believe there have been other modes of 

 applying heat suggested, but it is needless recording them. Let 

 us, therefore, see in what way the two most available modes 

 of heating, which are fermenting materials and fire heat, can be 

 used; thejatter, of course, including hot water, &c. 



To the fermenting materials supplying heat it is hardly 

 necessary to advert, as local circumstances generally point out 

 which must be used ; and useful as such an assistant is to the 

 forcing-gardener, there are many plants which cannot be carried 

 through the dark days with them alone ; for the steady warmth 

 given off by a bed of tan, dung, leaves, or similar substances is 

 not capable of being suddenly increased to meet the fluctuations 

 of temperature not unusual at Christmas or afterwards. A 

 sudden depression of, perhaps, 30° in the external atmosphere, 

 tells also to a certain extent inside a glass structure ; but fer- 

 menting material alone is incapable of any increased effort 

 likely to compete with this diminished temperature. In the 

 generality of cases, therefore, requiring a steady high temper- 

 ature in winter, it is necessary to call in the assistance of fire heat 

 as well ; and the latter being completely under command, and 

 being used more or less as occasion requires, the best results 

 follow, the union of the two beiDg certainly better than either 

 alone. Although there are plenty of cases in which fire heat 

 does the whole, and that very well too, still a body of fermenting, 

 material has advantages which no artificial combination in which 

 fire, water, and iron are alone employed can afford. 



Fire Heat. — Having adverted to the loss in all cases entailed 

 on the user of fire heat, I may here add that no one loses so 

 much as the forcing-gardener. With him combustion goes on 

 in one place, and the air required to be heated is separated from 

 the fire by large masses of brickwork. Possibly the fire is made 

 to do duty on some boiler, which sends its warmed fluid in 

 circulating currents through some long and intricate series of 

 piping, which in turn has also to be warmed, in order to afford 

 the tardy warmth given off to the atmosphere either above or 

 surrounding the pipes. Of course all their auxiliaries or appen- 

 dages have to be warmed by the fire before any heat is given 

 off, and, by the time the fire heat reaches the farthest object it 

 has to be applied to, it is divested of much of its warmth. 

 This is the evil, and how to remedy it has puzzled the learned 

 in such matters for many years ; and although much improve- 

 ment has been and continues to be made, by the better con- 

 struction »f fireplaces, the advance in heating horticultural 

 buildings faUs far short of what has been done to improve the 

 construction of sitting-room fire stoves, kitchen ranges, &c. ; 

 while gas, Arnott, and other stoves to heat shops, halls, and 

 public buildings have likewise undergone many improvements. 



Although the subject is, perhaps, not quite in order here, I 

 may say that one of the best heated churches I was ever in is 

 warmed on what is called Sylvester's plan of heated air. The 

 apparatus was made, I believe, at Trowbridge — at leaBt it bears 

 that name — and is unquestionably a great improvement on all 

 the modes of heating such edifices I have ever seen in use. 

 Of its economy I can say little ; but should suppose, by its 

 warming such a large volume of air, that the fire heat must be 

 carefully employed. Of its applicability to horticultural build- 

 ings I can also say little : perhaps, however, this mention may 

 draw forth more precise information on these points. 



Heated air has often been held in dread by the gardener, as 

 likely to contain some noxious gas fatal to his plants ; but, in 

 the mode of heating I allude to, it has none of the Arnott's- 

 stove stifling smell so often complained of, and it is possible 

 that for forcing purposes it could be still further improved or 

 purified. Heated air is unquestionably the most economical 

 way that fire heat can act on an atmosphere which it is neces- 



