Responses to Art in Conservatory Article

Responses to Maurice B. Adams’ “Art in the Conservatory and Greenhouse” paper given to  the Leeds Architectural Association

The Gardeners’ Chronicle, Volume 13, 31st January 1880.

In the admirable paper by Mr. Adams on “Art in the Conservatory,” it seems to me that he accords but scant justice to architects, gardeners, and horticultural builders, who have with very considerable success laboured in this direction, as witness the many beautiful conservatories and greenhouses to be found in almost every part of the country. I observe also that he quotes Mr. Hood’s rule for obtaining the proper quantity of piping to keep up a given temperature. {See Hood on Warming and Ventilalion, 5th ed.,pp. 116, 117.) There are elements of incorrectness in this rule which should be guarded against, as any one may see if they apply it in a test case. The discrepancy between the rule and the short method given by Mr. Adams, both for stoves and for early vineries, may be tested in this way. Take an early vinery 30 feet long, 20 feet wide, i foot of wall above floor level, and 3 feet of upright glass, allow an angle to give, say 14 feet of rafter, giving a superficial measurement of 1340 feet ; allow 140 feet for woodwork, and we have 1200 feet of glass. Proceeding by the above rule, we multiply by 14 to find the number of cubic feet of air to be warmed per minute = 1500. Now, say, for an early vinery to be started on December 1, and to be kept up to 70°—while, as we had, last year and this year, the outside temperature below zero, we must count upon 70° of difference between the external and internal temperature—then 125 x 70 = 8750 / 130 = 67 x 1500 = 100,500 / 222 = 452 feet of 4-inch piping (I drop the fractions) to heat a vinery 30 x 20. Now, taking the other method of the cubic content, 30 x 20 = 600 X 9 (average height) = 5400 / 20 (number of cubic feet to 1 foot pipe) = 270, little more than one-half the quantity. There must be something radically wrong here, when by one rule we get 452 feet as the j proper quantity of piping, arid by another rule 270 feet. The other point I want to direct attention to is where Mr. Adams says that the best aspect of a span vinery is east and west. We have always looked upon it as a kind of axiom that a span vinery should be placed north and south, in order that both sides might get the sunlight in nearly equal degrees, and that if placed east and west the Vines on the north side must suffer from being shaded by those on the south side. In all my experience I have found almost no difference of opinion on this point ; is it possible that practical gardeners and greenhouse builders have been labouring under a mistake here? A. D. Mackenzie, 2, Grove Terrace, Edinburgh.

At the conclusion of Mr. Adams’ paper there is a rule for finding the quantity of 4-inch pipe necessary for heating so many cubic feet of air to any requisite temperature. I venture to state that there is an error in the wording of the rule. We find “Multiply 125 by the difference between the extreme external and internal temperature, .and divide their product ….betwixt the temperature of the building and the pipes, &c.” I think that where I have left a dotted space the words ” by the difference” have been omitted; and this statement is supported by the example : — ” 125 X 55 = 6875 ; 6875 / 125 (the difference between temperatures of pipes and house).” T. H. Larkin, Eastbourne.


The Gardeners’ Chronicle, Volume 13, 8th February 1880.

Art in the Conservatory.— I have to thank you for publishing my paper on ” Art in the Conservatory and Greenhouse,” and can but be glad should its publication call forth some discussion among your practical readers, as my desire in writing the lecture was to acquire information as well as to give it, and I am fully alive to the fact that by publishing a technical paper in the Gardeners’ Chronicle I have laid myself open to the critical remarks of some of the leading horticulturists of the day. Undoubtedly a glasshouse of whatever kind should first of all be built in the interests of the gardener and his plants, but beyond this I would go, and urge that in most cases the houses themselves can, with a little thought and trouble, be made good-looking, and in some sense, at any rate, architecturally correct, whether they are simply wooden or more monumental erections. Your correspondent, Mr. A. D. Mackenzie, to use his own words, ” has been labouring under a mistake ” in directing attention to my remarks upon vineries. His mistake is evidently due to the fact that he had read only some disjointed extracts from my lecture which were published in a gardening contemporary ; indeed, that portion of my remarks referring to vineries was given only in last week’s issue of your journal, to which I beg to refer your correspondent. He will there see that I said ” for early vineries a half-span or rather lean-to structure is the best form of building, and that it should face the south, running east and west so as to have the benefit of the sunlight from morning to the evening.” Then to show further that this was entirely my meaning, I would further refer to p. 106 Gardeners’ Chronicle, January 24, 1880, the second line from the top. In my general remarks I said, ” a span-roof house should be placed with the ends north and south, as by this means each side secure an equal amount of sun.” Thus it will be seen that Mr. Mackenzie’s concluding satirical thrust at me about teaching practical gardeners, &c., is unfounded ; and I think the same may be said in the charge which he brings against me of doing ” scant justice to other architects and horticultural builders,” who have done much in the way of improving the appearance of conservatories. I clearly expressed my desire not to overlook such work, but it is equally evident that in so short a paper I could not enumerate a series or describe more buildings than I did. As to the rule which I gave for obtaining the proper quantity of piping to warm conservatories, I have only to say that it depends entirely upon the difference between the inside and outside temperature. Mr. Mackenzie makes this 70″, taking the outside temperatures as zero, but this, I take it, is unnecessarily low, as we do not get so low a temperature once in ten years, if so often. Taking the external temperature

At 26° the result is 283 feet of 4-inch pipe
At 24° the result is 297 feet of 4-inch pipe
At 22° the result is 310 feet of 4-inch pipe
At 20° the result is 324 feet of 4-inch pipe

while by the simpler rule I gave you get 270 feet, and for all practical wants this is sufficient, and 26° is low enough for ordinary calculations. Of course if anyone is willing to pay for more pipe it can easily be arranged by taking a very low outside temperature. I have not relied entirely on my own knowledge in the matter of heating arrangements and in calculating for them, but have availed myself of the experienced assistance of a well-known horticultural engineer, Mr. Walter C. Burden, of Loughborough. There can be no doubt that a simple formula in plain figures, more simple than Hood’s or any other that I know, is a want that very many people experience. The following query by a friend of mine was published in the English Mechanic last October, and as yet it has received no answer. I ask you to repeat it, as it gives my friend’s rule, and some of your mathematical correspondents may be able to answer his query ” Can anyone simplify this process, and put it in the usual shape ? It is for finding the length of piping required for greenhouses. Multiply the glass or exposed superfices in feet by eleven times the required difference between the outside and inside temperature, and divide the product by fifteen times the intended difference between the temperature of the water and the air of the house. The outside air is to be taken at 32°, and the water at 180° Fahr.” Surely this can be simplified, when no doubt it would be useful to your readers and Maurice B. Adams, A.R.I.B.A.

In reading what has appeared on this subject one cannot help wishing that some of the designers or builders of such structures could have profited by the remarks and borrowed a wrinkle or two, as In the majority of cases conservatories are mere prison-houses for plants, and ill-adapted for the purpose required. Architects, as a rule, know little or nothing of vegetable life ; they are great believers in bricks and mortar, stucco, and such-like ornamentation, but as to light and its need for the successful cultivation of plants that is largely ignored ; and hence it is that we see the dungeons that are frequently to be met with connected with mansions. What I should like to see is several conservatories to every house in the form of bay windows, instead of having dwellings as they now are, mere boxes with rectangular holes cut in the walls, through which no one can see out except straight ahead. By having projecting windows the vision can be carried in any direction and rooms made tenfold more pleasant, the spaces so created being just the places for standing plants, which when so situated .^fiord a daily feast of beauty unattainable in any other way. It is only those living in towns that know the joys derived from the window culture of flowers, and with better arrangements provided for them they might be had in every home. People attach great value to pictures and pay high prices for their possession, but once seen they are always the same, while in plants there are continual changes going on to watch, and much to instruct us in our daily intercourse with them. That the ove of plants is fast extending there can be no question, and it only remains for those who design our residences to break away from the monotonous style now so prevalent, and make them, not only fit habitations for man, but such that he may associate with the beauties of Nature. That this may be done any one can see where there is any departure from the old fashion, a striking instance of which I have recently met with, where a sort of double conservatory, one on each side, forms part of the house. In these plants flourish, and the song of birds is heard among them, the two combined lending such a charm as to make life pleasant within. J. S.

With reference to Mr. Adams’ recent article in your paper will you allow me, in hopes of receiving some practical suggestions, briefly to describe a conservatory, architecturally a success, but horticulturally a failure ? In shape it forms five sides of an octagon, and faces the south ; the floor is 3 feet below the house-floor level, to which four steps lead to the door communicating ; it is 14 feet wide by 12 feet long ; front height 6 feet, with roof span of 75 feet. It is glazed with clear glass except on the roof, most of which is obscured. It is ventilated at the bottom by four opening sashes, each 2 feet by 1 foot ; and at top by opening sash on roof, 3 feet by 1 foot. There is staging round about, with border underneath planted with Ferns, and cement water-tank, 6 feet by 3 feet, in north corner, to grow aquatic plants. It is heated with gas, and provision is made to carry off any escape. The plants growing are greenhouse, stove, and florists’ flowers, and none of them do well when taken into it, but go back every day ; some lose their leaves, others drop their flowers, particularly Fuchsias and Acacias. Foliage plants stand best, but they, too, suffer. .S.[The gas-heating is probably at fault ; but in any case such a house is not a proper one for the cultivation of small plants. Eds.]

The Gardeners’ Chronicle, Volume 13, 14th February, 1880

Art in the Conservatory.— I have read Mr. Adams’ reply to my letter, and I am pleased to find that when he gives the proper aspect of a span-roofed vinery as east and west his meaning is that it should be placed north and south. The phraseology is somewhat confusing and unusual, which has led me to attribute to it a different meaning. My reading of the article was taken from the Building News, where it appeared on January 16 and 23, and not from any of your gardening contemporaries, as Mr. Adams supposes. I regret that upon the other point referred to, my rules for obtaining the proper quantity of piping to keep up a given temperature, I am not able to agree with him. I pointed out in my former letter that the more elaborate rule given was copied from Mr. Hood’s work. Mr. Adams says in his reply, ” Taking the . . . . simpler rule I gave.” Will he be surprised to learn that this simpler rule is also copied from Hood, and is, as well as the other, more than forty years old (see Hood, first edition, 1837, pp. 17 to 25). Mr. Hood evidently was a man of great ability and research, to whom all horticulturists and heating engineers are much indebted, and as he himself, in his preface to the later editions points out, it is very unfair to borrow rules and tables from his work “without acknowledgement.” Mr. Adams departs from Hoed when he gives 26° as being low enough for ordinary calculations : Hood gives 10°. On the principle that the weakest link measures the strength of the chain, even 10° is not low enough. We have had in Roxburghshire and Berwickshire in December last a temperature of 15° below zero. Mr. Thomson, Clovenfords, if I remember rightly, registered 12° below zero ; therefore it is necessary, in Scotland at least, to take a much lower figure than even 10°. In the winter of 1878-79 we had it repeatedly below zero, so that, instead of (as Mr. Adams says) experiencing this severe cold once in ten years, if so often, ten times in two years is nearer the truth ; therefore, to take 26° Fahr. as our basis for calculating our heating apparatus when we have experienced a temperature of 30° or 40° lower is surely misleading. What the qualifications of Mr. Burden of Loughborough may be I know not, but have every reason to believe they are what is represented ; at the same time I think Mr. Burden will not be slow to admit—as indeed all must admit who have looked at the subject—that the two rules quoted by Mr. Adams are, to .say the least of it, contradictory to a large extent. Mr Adams gives another rule, but “neither in this does his witnesses agree.” Let us apply this last rule of his friend’s to the span vinery as formerly, with 1200 feet of glass = 1500 feet per minute. The rule, multiply the glass in feet (1500) by eleven times the required difference between the outside (always taken at 32°) and inside temperatures 70” (38°), and divide by fifteen times the intended difference between the temperature of the water (always i80°) and the air of the house (70°), 110°, thus — 38 x 11 = 418 x 1500 = 627,000 / 110 x 15 = 1650 — 380 feet of pipe. Three rules are given— one gives 452 feet, another 380, another 270. But if we are to fix upon a temperature, say 26° to suit our rule, I have no doubt the figures may be made to correspond. I think, however, we should endeavour to find a rule to suit our temperatures rather than fix upon a certain temperature to suit our rules. And I hold that whatever our rules are— to be safe, at least for Scotland and the North of England—we must fix upon a point as low as zero. Allow me to say that I look upon Mr. Adams’ paper as a most able and, as far as could be expected in the circumstances, an exhaustive treatment of the subject as a whole, from which no doubt good results will flow ; and, notwithstanding anything said in either of my letters, I am very glad indeed to have had the opportunity of reading it. A. D. Makenzie, 2, Grove Terrace, Edinburgh.

The Gardeners’ Chronicle, Volume 13, 21st February 1880

Rules for Heating Conservatories. — Mr. Makenzie’s letter in last .Saturday’s Gardeners’ Chronicle concludes his correspondence under the heading of “Art in the Conservatory and Greenhouse” with some pleasant remarks on my late lecture, reported in your pages, and his allusions, of course, have given me satisfaction ; but I must not therefore hesitate to remark that he himself has failed to contribute anything fresh on the subject. He has only told us what was already well known about the branch of the subject to which his critical remarks more especially refer, viz., the proper modes of calculating the quantity of hot-water pipes required for heating conservatories. The substance of his letters resolves itself into two counts. Firstly, that all the rules I gave could possibly be made conflicting, and secondly, that I had cribbed them without acknowledgment from Hood’s work on Heating and Ventilation, a book to which he says he, in common with all engineers and horticulturists, is indebted. Permit me to say with reference to the last indictment that personally I had never seen a copy of Hood’s volume till one day last week, and that instead of borrowing from any printed rules I consulted an experienced horticultural engineering friend whose advice I coupled with my own practical knowledge of the matter ; and should it be found that such combined information agrees with what was already known by experts, I cannot see that there is anything to cause surprise if the rules thus recommended correspond somewhat with those set forth perhaps years ago in standard works on the subject. Mr. Makenzie’s first count, however, is not so readily answered, and I can but regret that he made no attempt himself to solve the difficulty which he has thus brought forward. He simply laughs at me, saying, “Ha! Ha! your rules are conflicting.” But surely this is a very commonplace thing for so able a correspondent to do unless he furnishes me with a better and more reliable rule. I am not an engineer, neither do I pretend to be a horticulturist, but as an architect I have spared no pains to find such data as should be easily read as a rule to be more generally applicable and yet as concise and simple as those already referred to. I care not how drastically criticised my rules may be, provided my critics will furnish better ones themselves, for which no one would thank them more than I. Will not some of your practical and experienced readers who have not yet spoken, answer my question by giving a better rule by which the proper quantity of hot-water piping may be secured for working without waste and needless outlay ? Reliable information is certainly needed on this point by very many besides myself. Maurice B. Adams, A.R.I.B.A., Bedford Park, Chiswick, W,

The Gardeners’ Chronicle, Volume 13, 6th March 1880.


YOUR readers must have felt indebted to Mr. Adams for his paper on Art in the Conservatory. It has given rise to considerable variety of opinion and some discussion. The subject is, however, by no means threshed out. Nowhere is Art more needed, nor less often found. Not that I believe in or desire what are called artistic conservatories : these have been mostly the toys or crotchets of architects, and the horror and despair of cultivators. At one time, and that not so very long ago, no one was considered qualified to plan or put up a glasshouse but an architect or great builder. The results were often highly ornate and expensive houses of the least possible use for cultural purposes. Attached conservatories, especially, destroyed rather than conserved plant life ; they were made to harmonise and fit in with the mansion —no matter whether they suited the plants or not. As a rule, they were far too lofty and too dark for cultural purposes.

As the nature and requirements of plant-life became better understood, there was a sudden rebound from these pretentious dormitories or hospitals to mere glass sheds. Like most reactions, the rebound from excessive formality to severe simplicity went too far. Cultivators had learned by bitter experience to hate the name of art as applied to glasshouses ; architects and all their horticultural works were alike shunned and condemned. Not only was a new race of horticultural builders called into existence, most of whom did good work for horticulture by building houses to suit the plants rather than to please the eye, but almost every successful grower became his own builder. The glass erections slipped from the hands of architects into those of gardeners. This was a decided gain to horticulture, but it is no disparagement to practical men to say that the change was not all gain or wholly for the better. Many good growers proved indifferent designers or builders, as the numbers of mere glass sheds up and down the country testify.

Horticultural architecture has now assumed such national importance as to require assistance of the best taste and the highest talent the nation has to bestow upon it. It is no disparagement of the practical talent which is the very backbone of horticulture, to affirm that the assistance of architects may be needful to design and give plans for the construction of conservatories and other glasshouses. .Such plans should, however, invariably be submitted to gardeners in regard to their internal and cultural arrangements. In a word, the architect may at times be required to find taste and to provide stability and safety— the gardener all else the plants need. No doubt gardeners often have found both, and some so-called gardeners’ houses are among the most ornamental as well as the most useful to be found up and down the country. Still we look upon it as one of the most promising signs of the times, that architects like Mr. Adams are turning their attention to the subject of Art in the Conservatory ; for while we may be said to teach and represent the highest art in the plants grown in glasshouses, we are also solicitous that the buildings themselves should be artistic. Mr. Adams also seems to be fully alive to the importance of light, heat, and air to plant-life and healthy growth. There is little to be added to these essentials— only those of occasional shade and an abundant supply of soft water, which may generally be collected from the roofs themselves.

But it is most important to impress on all concerned the fact, that the most severe regard for utility is by no means incompatible with a proper amount of ornament. Not only are utility and beauty compatible ; but the latter forms no small portion of the former, inasmuch as congruity, that is, fitness, is an essential element of beauty. For example, all water jugs, vases, glasses, may be said to hold water equally well ; but the more chastely they are designed, the more elegantly formed, or the more perfectly finished—in a word, the greater their beauty, the more pleasant are they to look upon and to use ; and thus their utility is enhanced in the exact ratio in which their beauty is heightened. The same remark would hold good of dwelling-houses, household furniture, the formation and adornment of gardens, &c. In fact, there seems to be far more truth than appears on the surface in the statement that beauty is probably the most useful quality or thing in the world.

Be that, however, as it may, it is as possible as it is desirable to combine beauty with utility in our conservatories and other glasshouses. Those attached to, or forming portions of, mansions or dwelling-houses, should be expressions of Art in their external appearance as well as models of cultural convenience in their internal arrangements. The great majority of conservatories are too lofty. For cultural purposes few need exceed a height of from 6 feet to 15 feet. Of course houses for Camellias, Rhododendrons, Tree Ferns, Palms, &c., may need to be more than double or treble the maximum height here indicated ; but for all round conservatories—that is, houses in which to grow flowers, or preserve such plants as Pelargoniums, Fuchsias, Heaths, Azaleas— these heights will prove ample. For it is found in practice that not only must plants be exposed to the light, but many of them thrive best when their heads are pretty close to the glass. The cultural failures in so many architectural conservatories arose quite as much from their extreme height as from their opaqueness. The plants, instead of developing into fine specimens, seemed always engaged in a race for the glass roof, which attenuated them into semi-skeletons. By placing the roof as close to them as is compatible with practical attention to their wants, and a full display of their beauty, the plants thrive better and it costs less to keep them warm.

The latter is a very important point in practice, for whatever ratio of proportions of pipe to area of cooling surface is adopted it is certain that the less air there is to be heated the less pipe will be needed and the smaller the coal bill. We would rather not pronounce ex cathedra on the .amount of pipe needful per cubic foot of air. The great practical point is to have sufficient pipe. Pipe is bought but once, coal annually, and hence in the end pipe is far cheaper than coal. As much or more heat may also be diffused through the atmosphere of glasshouses from a greater surface of pipe, moderately warmed, than from a smaller quantity of pipe at a higher temperature ; besides, the risk of injury to boiler and pipes rises with the temperature. As in running it is the speed that kills, so in heating it is the pressure that bursts boilers, tries joints, blows the water out of pipes, smelts furnace bars and doors, and not seldom ruins all ; hence the wisdom of over rather than under piping conservatories and all glasshouses. In all calculations of pipe to area it is wise to take zero as a starting point, as zero is reached occasionally ; and meanwhile and always the extra piping will ensure greater economy of fuel ; hence conservatories should have at least 1 foot of 4-inch pipe to every 20 or 25 cubic feet of air ; and plant stoves^ early vineries, and forcing-houses I foot of pipe to every 15 or 20 cubic feet of air.

There is also much room for the exercise of skill and even art in the form and disposition of the pipes used. Cylindrical pipes are probably the cheapest and safest, but it seems doubtful if they are the most economical. Pipes, or rather trays, 2 inches deep, a foot wide and a yard long, have been thought to radiate more heat from an equal amount of fuel. Oval pipes have also been recommended in our pages.

The usual plan of sinking the pipes beneath the iron gratings is the most artificial that could be conceived. Most of the heat absorbed by the bottom and sides of such chambers is lost to the warming of the air of the house. There is also probably a good deal of loss alike of pipe and heat in the usual plan of carrying pipes all round the conservatories and other houses to be treated. Heat, the most volatile force in Nature, is led with iron reins to every possible point, as if it were motionless as lead when left to itself It would seem almost as reasonable to mount one’s hunter in a farm waggon, and proceed thus after the hounds.

By the concentration of heating surfaces with ornamental coils, radiating tables, boxes, stages, shelves, a reduction of area might be effected, and a more thorough circulation of air insured. The latter is of the utmost importance from a cultural point of view. It is not enough that the air should be warmed, it must also be moved. Heat is the great moving force, and yet most of our heating arrangements proceed on the principle of distributing an equal amount of heat to every part of the house. In so far as it is possible to accomplish this, the internal atmosphere is forced to remain still and stagnant. Probably the next great advance in horticultural heating will consist in arranging the healing surfaces at convenient points at considerable distances apart. The heated air will speedily distribute itself, and in its search after an equilibrium of temperature the’ whole atmosphere of the house will be kept in perpetual motion. By thus concentrating the heat at different and relatively distant points, and raising the whole heating power well out of the ground, readily available sources of bottom-heat may easily be provided for cultural and forcing purposes, and the whole of the heat be utilised and turned to better account.

A good deal more art as well as common sense might also be employed to good purpose in the ventilation and shading of conservatories, as well as in the storing and distribution of water for cultural purposes ; the law of proportion is also too often grievously sinned against in their construction. Of these and their most inartistic internal arrangement we shall probably have something to say on a future occasion. D. T. Fish.