812 



JOCBNAL OF HOBTIODLTUBE AND COTTAGE QAEDENEB. 



( April 20, 1876. 



will be the beginning of September, I remove them to a shelf 

 where they do not receive water, bnt where plenty of atmo- 

 spheric moisture is afforded, as the main object is to keep the 

 corms plump. I do not allow placing them in a corner under 

 the stage, or some such place, to get them out of the way, 

 as is often done. The house I store them in is kept through 

 the winter mouths at a night temperature of from 48° to 52°, 

 rising to about 60° during the day. I have found when the 

 pots are out of your notice, and when removed to be shaken 

 out, you will find the corms very much shrivelled, and de- 

 pend upon it you will never succeed with shrivelled corms. 1 

 consider sound corms to be one of the main points of success. 



I remove the plants from the shelf early in January, and 

 shake out carefully, not injuring the fleshy roots. In potting 

 this time I use a rather stronger compost. I find the plants 

 succeed remarkably well in two parts good fibrous loam rather 

 fresh, one and a half part decayed manure, if obtainable cow 

 manure, with half a part leaf mould, using plenty of silver 

 Band, but not peat, placing the corms in the same sized pots. 

 I then place them in the Cucumber house until they begin to 

 break freely ; they make roots very fast after this time, and their 

 working round the pots is a signal that they require a shift to 

 32-sized pots. I then place them back again for about ten 

 days, and then remove them to a house having a temperature 

 from 50° to 60° during the night, allowing with sun heat a rise 

 to 70° to 75° by day. As soon as they have filled these pots 

 with roots I give them one more shift into their blooming pots, 

 which is done by the middle of March. By that mode of 

 culture the plants grow luxuriantly, with foliage covering the 

 pots — in fact it is with difficulty that they can be watered. They 

 measure fully 2 feet across, and are just throwing a fine lot of 

 flowers. I may add that they have all the light procurable, 

 for I never shade them until in fiower. I have also a strong 

 objection to the use of the syringe, but they cannot have too 

 much atmospheric moisture. — J. Pitheks, The Gardens, Mun- 

 ster House, Fulham Road. 



[We have seen Mr. Pithers'e Gloxinias,", which are very 

 superior in every respect.] 



DISTBIBUTION OP HEATING SUEPACES. 



Since the introduction of heating by hot water and cheap 

 glass horticulture has progressed rapidly, especially in the 

 higher cultivation of tender flowers and forced fruits. I do 

 not wish to be understood as attributing the advance solely to 

 cheap glass and a better system of applying artificial heat, but 

 am fully prepared to award advanced skill its due. We are 

 nevertheless perforced to ask. What is modern skill without 

 modern appliances ? Advanced skill linked to heavy rafters, 

 light-obstruoting saehbare, small panes of glass with broad dirt- 

 holding laps, ventilation admitted by wide-distant gaps, and 

 imperfectly-formed flues cannot produce perfect results. 



To flue-heating I have always had a decided aversion. Merit 

 it may have, but it compares disadvantageously with heating 

 by hot water. To the construction of light airy houses no ob- 

 jection can be made on the score of economy as compared with 

 " all wood " structures of a former date; but to heating with 

 flues and hot water we have to face an increased expenditure 

 by adopting the latter aa compared with the former. Though 

 heating by hot water entails a considerably greater first outlay 

 of capital, yet we are nevertheless bound to admit the claims 

 of hot water to be very much higher in efficiency and in 

 resultant economy than the most approved modes of flue- 

 heating. There is not the least doubt of the greater first cost 

 of heating a house by a hot-water apparatus than the heating 

 of the same, or a similar house, with a flue or flues, and it is 

 not questioned but that the working expenses will be as great 

 by the hot-water heating as by the flue. To arrive at the rela- 

 tive values of the two systems we must seek them in the results. 

 If it can be shown that a flue costing only a third the cost of 

 a hot-water apparatus is worked at no greater expense, and is 

 as efBcient as hot- water heating, then we are wrong in our esti- 

 mate of the values of the two systems ; but I must submit 

 there is a wide difference in the work performed — in its higher 

 quality as shown by the more healthful plants, and more 

 certain and safer performance. It is not asi^umed that hot- 

 water heating is infallible, for boilers or pipes crack some- 

 times, but it is free from many of the objections which may 

 be taken to flue-heating. 



Some of the many failings of flue-heating are: — 1, A sur- 

 face heated to a temperature prejudicial to plant life at its 

 entrance to the structure. 2, From its many joints the 



liability of its parts to crack, admitting by those crevices the 

 noxious vapours to mingle with the atmosphere and tell pre- 

 judicially upon the health and vitality of the plants. 3, The 

 Liability of fouling with soot, diminishing the power of the flue 

 surfaces to the heat passing through. 4, The danger of the 

 Boot igniting, and the extreme uncertainty of the flue not 

 giving way under the great heat consequent on firing of the 

 soot. I might tell of the uncertainty of action when a 

 sudden frost demands the use of the fires — the smoke and 

 heat declining to go along the fine, or very tardily, giving out 

 smoke from every crevice it can find to make its exit through, 

 and keeping the attendant breathing as best he can in smoke 

 for hours in hope that he may defy frost and satisfactorily 

 present himself to his superior or employer. I have had such 

 an experience of fines smoking, overheating, and breaking 

 down as to detest their sight and mention, and am surprised 

 that flue-heating at this day should have its advocates and (as I 

 notice from your correspondents columns) its adopters, but am 

 gladdened to notice your replies show you are no advocate of 

 them, or only for small houses, and not always for them, for 

 you oftener direct to heat with hot-water pipes than flues. 



With this " parting kick " at flues I have to consider that 

 in the distribution of heating surfaces in horticultural struc- 

 tures the surfaces are in heating by flues and hot-water pipes 

 materially diverse, being very nearly of a uniform tempera- 

 ture throughout the extent of pipes, not having a difference of 

 more than 2° in every 100 feet, and at no point can it be higher 

 than boiling (212°), and this only in case of overheating ; but 

 on the contrary, an overheated flue (red in the dark) attains 

 a temperature of 752°, its lowest ignition in the dark being 635'. 

 These are of course extreme cases, but as they do occasionally 

 occur it is necessary to note them with a view to their avoid- 

 ance, for the higher the temperature of the heated surface the 

 more speedy is its effects upon the atmosphere. Where the 

 flue is too quickly and too highly heated the moisture is by the 

 ascending heat driven against cooler surfaces, to be by them 

 condensed ; evaporation is much more rapid, which applies not 

 only to the plants and the atmosphere, but to the soil. In 

 heating by flues it is common to have the furnace in a shed, or 

 so that it can be fed from that side, the heat and other pro- 

 ducts of combustion being taken across the end, along the 

 front, across the other end of the house to the back wall, and 

 if the house were small along the back of the house to the 

 point from whence it started, and making its exit by a chimney 

 in the back wall. 



Though we pride ourselves on our advancement we have 

 made no improvement on the distribution of flue or hot-water- 

 heated surfaces. We take the hot-water pipes along the ends 

 and front of lean-to's and along the sides of spans ; the object 

 being, that as heat ascends more quickly than it is diffused 

 laterally, to have the radiating surface at the lowest point, 

 from the known fact that it will rite to the highest. With 

 this arrangement I am not going to find fault : it is probably 

 the best arrangement of the hot-water pipes when the object 

 is not to maintain a higher temperature than will ensure the 

 safety in severe weather of greenhouse plants, or to assist 

 Vines at starting and ripening their fruit, to save the blossom 

 and young fruit in Feaoh or orchard houses from frosts in 

 spring, and the ripening of the crop and wood in those struc- 

 tures if necessity so requires ; but I must take exception to 

 this arrangement of the pipes being suitable when a high tem- 

 perature is required and when forcing is carried on at the 

 dullest and coldest half of the year. The circumstances are 

 very different in the two cases. By the former the heat by 

 which growth is prompted is for the most part natural— solar 

 —admitted by the glass, and by the same means retained, the 

 artificial heat being auxiliary and not depended on when growth 

 is proceeding rapidly. 



It is all very well to tell us how many feet of 4-inch piping 

 at a given heat will enable us to maintain the temperature in 

 a given structure. It serves a purpose, no doubt, to put all 

 the pipes at one side of the house or both sides, placed along- 

 side and over each other — just about as good as the concen- 

 tration of the heating medium of a hall in a coil of pipes 

 hidden by an ornamental screen ; but the purpose served is 

 certainly not what vegetation has by nature afforded — viz., an 

 equalisation of the heat transmitted. There is a limit even to 

 the radiation and penetration of natural heat ; and in that of 

 artificial its limit of penetration even in an enclosed structure 

 is to be found, for a hot-water pipe giving off heat at 160° will 

 have at a foot distance from the pipe a considerably lessened 

 temperature, and materially decreased one at 6 feet, decreasing 



