going on steadily and prosperously. At a meeting of the Committee, April 14., the first two pensioners were named: they were, the widow of an aged gardener, and an aged and infirm gardener; both recommended by respectable gardeners holding first-rate situations, and by the clergymen of their respective parishes. At the same meeting, a donation of ten guineas was received, together with a few minor donations, two life subscribers, and a dozen annual subscribers. A vote of thanks was passed to such proprietors and editors of botanical and horticultural periodicals as had published the Rules and Regulations of the Society gratis; and a hope was expressed that the practice would be continued and extended, at least for some time, till the Society obtained ample funds. — Cond.

SCOTLAND.

Cottage Windows.-The Highland Society of Scotland, desirous of contributing by every means in their power to improve Scotch cottages and their gardens, has offered premiums for the "best and approved" cottage window. This will probably do much good. Scotch cottages are in general miserable hovels, and their windows small square holes with a fixed frame containing four panes, not made to open for ventilation. - Cond.

Irrigating Meadows with Liquid Manure. - This has been done to a considerable extent for some years past close to Edinburgh, by causing the liquid part of the contents of the common sewers to flow over certain low-lying grass lands. The effect has been most injurious, both to the inhabitants adjoining these irrigated lands, by contaminating the surrounding atmosphere, and to the animals which feed on the grass produced, by destroying in a short time the digestive powers of their stomachs. A very interesting pamphlet has been published on this subject, entitled, Papers relating to the noxious Effects of the fætid Irrigations around the City of Edinburgh, 8vo, 1839, A. and C. Black. By this tract it appears that no horse or other animal will eat a particle of the produce of these meadows, either while growing, or when first cut; and that cows "when first put to eat it have for some days an absolute loathing, and can hardly be got to feed upon it; but when they do, it causes an immense flow of milk, which is kept up by this grass, and what is called dreg [brewer's wash]; but whenever the supply of this grass becomes short, they are found to be incapable of digesting the usual fodder of cattle, and completely diseased, and get unfit for any purpose almost." It is lamentable to think that either individuals or public bodies should have it in their power to tamper with the public health, in the manner which appears to have been done at Edinburgh for some years, by the irrigation of these meadows; but we trust the practice will in a short time be put down.—Cond.

ART. III. Caledonian Horticultural Society.

THE Spring General Meeting of this Society was held in the council room, at the Experimental Garden, Inverleith, on the 5th of March, Duncan Cowan, Esq., in the chair. The show of flowers and fruits was not extensive; but the specimens were select, and in general excellent.

For fine varieties of Camellia japónica, two premiums were awarded: the first to Mr. John Addison, gardener to the Earl of Wemyss, Gosford House, for C. Donckelàeri and imbricata; and the next to Mr. John Young, gardener to Thomas Oliver, Esq., Newington Lodge, for C. Donckelàeri and Vandèsia cárnea. A curious specimen of Gray's Invincible Camellia, reared by Mr. Kelly, at the Inverleith Nurseries, having two kinds of flowers on the same stem, attracted much notice. All these plants were in pots; but there was also a rich collection of cut flowers, consisting of 18 varieties, from Balcarres garden, which excited great admiration. Three premiums were awarded for choice specimens of the beautiful genus E'pacris: the first to Mr. Addison, Gosford, for E. nivàlis, and a new variety of E. variábilis; the next to Mr.

Young, Newington Lodge, for a large plant of E. impréssa, clothed with its crimson flowers, and E. campanulata álba; and the third to Mr. Robert Watson, gardener to David Anderson, Esq., of Moredun, for E. impréssa and nivalis. Of Azalea, possessing the Chinese character, three specimens were produced, two of them particularly large and fine; for both of which premiums were voted. One was from Mr. Watson, Moredun, marked Azàlea hýbrida, with purple flowers; the other was from Mr. James Smith, gardener to Professor Dunbar, Rosepark, and stated to have been raised by the professor from seeds of A. phoenicea crossed with A. índica álba; the flowers white, but not fully expanded. The finest exotic shrub exhibited was a noble plant of Rhododendron arbòreum var. ß, in full flower: this was from the garden of the Earl of Rosslyn, at Dysart House, and the silver medal was voted for it, to Mr. John Blair, gardener to the earl. A premium was likewise voted for an admirable specimen of Erica hyemalis, decked from base to summit with its violet-coloured blossoms. This was from Gosford garden.

It is rather remarkable that there was not on this occasion any competition in tropical Orchideæ, although the cultivation of that interesting tribe is now pretty general, wherever stove heat can be commanded. Ample amends was made, however, by the exhibition, in the central window of the council room, of a very well grown specimen of Dendrobium Pierárdi, from the Society's hot-house, under the management of Mr. James M'Nab, the specimen being treated as an air plant with long pendent shoots hanging as from the branch of a tree, and at present adorned with its delicate pink tinged flowers.

A premium was voted to Mr. John Macnaughton, gardener to John Wauchope, Esq., of Edmonstone, for a collection of ornamental plants, including two seedling camellias raised in 1833, and now first showing flower; and also a large flowering specimen of Acàcia hastulàta, raised from seed received from King George's Sound.

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There was, this season, a deficiency in the show of dessert pears. mium was, however, assigned to Mr. James Simpson, gardener to Captain Wemyss, M.P., Wemyss Castle, for very good samples of Beurré Rance. In apples, several competitors appeared, and the fruit was uniformly in high preservation. Three premiums were awarded the first to Mr. William Thom, gardener to David Anderson, Esq., of St. Germains, whose kinds were, Red Cluster, Ribston Pippin, Fulwood, Pomme-roy, Orange Blenheim, and Spencer Pippin; the next to Mr. William Sharpe, gardener to Sir John Stewart Richardson, Bart., of Pitfour, the sorts being Yorkshire Green, Ribston Pippin, New Ribston, Golden Pippin, Nonpareil, and Winter Redstreak; and the third to Mr. William Rintoul, gardener to James Balfour, Esq., of Whittingham. Two baskets of Mushrooms, affording examples of two distinct varieties of Agaricus campéstris, were honoured with rewards: the one set was raised by Mr. Macnaughton at Edmonstone, and the other by Mr. Brewster at Balcarres. A basket of the tubers of Tropæ'olum tuberosum, of large size, was sent from the garden of the Dean of Faculty at Granton, and a premium voted to Mr. John Reid, who raised them. It does not appear probable, however, that this root will come into esteem as a culinary article.

A letter from M. Réné Langelier, nurseryman, near St. Helier, Jersey, was read, announcing a present to the Society's garden of more than 100 fruit trees, including all the most choice pears cultivated in the Channel Islands. Dr. Neill stated that the trees had arrived in safety, and that the superintendant, Mr. James M'Nab, had ascertained that 76 of the sorts were new to the Society's collection. A medal was voted to M. Langelier, and his name was immediately enrolled as a corresponding member of the Society. Various seeds of the culinary plants cultivated in Sennaar and Kordofan, brought home by Mr. Holroyd, the traveller, were presented by Professor Don, of King's College, London, and thanks voted.

Several communications on horticultural subjects were then read by the secretary; particularly on a mode of preventing and of curing mildew and green fly on wall-fruit trees (by means of a paint composed of flower of sulphur

and soft soap), by Mr. Sharpe, Pitfour; on the cultivation of Chrysanthemum sinénse, by Mr. Macintosh, Archerfield, who excels in the management of that splendid winter flower; and remarks on the most hardy and productive fruit trees known in Lancashire, by Mr. Garnett of Clitheroe. —P. N.

ART. IV. Retrospective Criticism.

ERRATUM,-In p. 229. line 1., for "inverted cylinder read “inverted

cone."

Remarks on Mr. Penn's Mode of Warming and Ventilating. — The excellence of Mr. Penn's method of warming and ventilating buildings appears to consist in the very uniform degree of moisture which it produces in the atmosphere. The heated air which enters the house has already received a dose of moisture nearly sufficient to saturate it, and has not to seek its moisture among the plants, as is generally the case. In most plant-houses the pipes are placed under the front shelves, at a considerable distance from the floor, and the atmosphere is moistened by syringing the plants, or throwing water on the floor and shelves. How greatly the state of an atmosphere so produced differs from that of Mr. Penn's houses, a little consideration of the annexed sketch will show. It is the section of a house heated by pipes under the front shelves; and it must be borne in mind that the capacity of air for moisture varies with its temperature, so that air which was saturated at 56° becomes very dry when heated to 70°.

The sketch, fig. 41.,

is the section of a house heated by pipes under the front shelves. The arrows (numbered) indicate the course of the current of air. At No. 1. the air comes heated from the pipes (p) and extremely thirsty; at No. 2. it finds moisture among the plants, and rising from the damp and warm shelf (slate, of course); at No. 3. it has parted with some of its heat; it is now supersaturated, and is parting with its moisture deposited on the glass; at No. 4. it is in the same state;

at No. 5. it has ceased to lose heat or moisture; at No. 6. and 7. the same; at No. 8. it again comes within the influence of the pipes, and is heated, becoming again very dry. Now the air which descends to the floor (ff), in the first place, is a small and feeble current, and, secondly, is nearly saturated, so that it can take up little moisture; what little it does get is because the floor, being slightly warmed by the radiation of the pipes, warms, and at the same time moistens, the air; but, nevertheless, the air at No. 1., in which air a visiter walks, is anything rather than saturated. My belief is, that air nearly saturated is always agreeable to the feelings. Dry air, which is absorbing moisture, is anything but agreeable. Hence the unpleasant sensation in orchidaceous houses, Now it is unnecessary to show how Mr. Penn's plan obviates all

these defects, and produces a uniformly saturated atmosphere which must be wholesome alike to plants and men.

There is a fact, which I have often observed in a small stove devoted to the cultivation of Orchideæ, which rather confirms this theory. This stove is furnished with most abundant appliances for moistening the atmosphere; about 15 square feet of water surface to 80 sq. ft. of glass. Of this water surface, 8 ft. are always at from 100° to 145°; the remainder varies from 80° to 85°, being warmer than the house both by night and day and all this is above the level of the heating pipes. The atmosphere, therefore, is, I believe, damper than that of almost any other orchidaceous house in England; and at this season the leaves of the plants are every morning covered with an almost tropical dew, standing in large drops all over them. Now in this stove, when the awning is on, and radiation from the glass, and consequently deposition from the air, much impeded, a temperature of 80° is by no means unpleasant. In five minutes after the awning is off, that same atmosphere becomes most oppressive, I believe because it has lost a portion of the water which it held in solution. — J. R. Sevenoaks, April 9. 1840.

On Mr. Penn's Method of Ventilation, and Mr. Rogers's Conical Boilers. The discovery of the best method of heating buildings being a subject of great importance in horticulture, I have perused with much attention and interest the several articles in your valuable Magazine for March, and I beg to offer the following remarks, as the conclusions of a practical man.

I have always been of opinion that the healthiness of plants, and their complete developement and perfection, are best secured by a moderate degree of ventilation, in opposition to that plan which would assert perfection to consist in keeping plants without any change of air whatever. I am, however, at a loss to understand how this is accomplished by Mr. Penn's process.

From your description, and the diagrams which are given, no change whatever can occur in Mr. Penn's arrangement, which merely provides for the continual reheating of the same air over and over again. If this be the case (for no mention is made of any method by which the foul air can escape), in what does this plan differ from every other method of heating by hot water? In all buildings heated by hot-water pipes, there must, of necessity, be a constant motion in the air; for those particles of air which come in contact with the pipes become expanded by the heat, and rise upwards, their place being supplied by colder and more dense particles. A continual motion is thus kept up in the whole atmosphere; for such is the extreme mobility of the particles of air, that a current, however small, established in any direction, will draw into its vortex many thousand times its own bulk of the same fluid.

If, then, the plan affords no change of air, and only produces a circulation among its own particles, similar to that effected by other arrangements, in what, allow me again to ask, does its excellence consist? From the encomiums passed upon it by you, I am disposed to think I misunderstand you; and, if so, shall feel greatly obliged, in common, no doubt, with many others of your readers, if you will set me right.

But there are other reasons why I am disposed to doubt the superiority of Mr. Penn's plan. By placing the pipes in a drain or tunnel, it is certain that the heat cannot be so regular as when the pipes are distributed in the house itself; nor can the same amount of surface produce the same temperature, as, when they are exposed, the air begins to rise with the smallest possible increase of heat.

It is certain that less than one degree of heat will cause the air in contact with the pipes to ascend; but, when the heating surface is enclosed in a drain, it requires a much greater force of heat to cause its ascension, on account of the diverging currents which are produced, and the friction of the air in passing through the various gratings, tunnels, and apertures. This is exemplified in many cases where large buildings have been warmed by a hotwater apparatus placed in the basement, and the heated air is brought into the

rooms through gratings placed in the floor. The same effect must take place in this apparatus of Mr. Penn's; and I feel convinced, by practical experience, that it is impossible to produce such a high temperature and so uniform a heat by enclosed pipes, as by those which are freely exposed in the building. Another advantage claimed for this apparatus appears to me more than doubtful. It is stated that, by throwing water into the tunnel, any degree of moisture may be imparted to the air; but on this subject I would remark that air absorbs moisture only in proportion to its heat; and, as in this case it is heated by the pipes after it has passed through the tunnel, it does not appear to me that it can ever be saturated by this means.

The sixth and last claim which you state this plan has to public notice is, that, "in the atmosphere of London, where the air is charged with soot and smoke, Mr. Penn's improvement will admit of forming a green-house or stove, with much purer air than can be obtained by admitting the external atmosphere according to the usual means of ventilation, which will not only be better for plants, but for persons going in to examine them." This passage I do not profess to understand, and therefore can offer no remarks upon it; for it appears to me, that, as Mr. Penn draws the air required for ventilation from the external air, that which he thus uses must be the same as is obtained by other people.

With respect to the Conical Boiler of Mr. Rogers, I would also offer a few remarks. Your correspondent, Mr. Beaton, states that when this boiler was first used it was in the form of a vertical cylinder, “which did not answer perfectly, wasting much heat:" but, in another part of his letter, he states, "there is great inconvenience experienced by the formation of steam, and he therefore thinks it will be better more of a cylindrical form," that is to say, of the very form which experience has shown wastes much heat. It would, therefore, appear, that either Scylla or Charybdis must be our fate, when we use this boiler.

Mr. Rogers has himself, with the greatest fairness, noted several of the inconveniences which attend the use of his boiler, and which have induced him unwillingly to relinquish the old form for that proposed by Mr. Shewin. These inconveniences, he states, were, the liability to derangement, and damage to the grating, as also the rapid wear of the copper boiler. If then, on the evidence of the avowed advocates for this kind of boiler, we find that, in order to avoid a paramount evil, we must adopt a shape which wastes much heat, that is also liable to get out of order, and that has sometimes been found" corroded in a few months by the sulphur disengaged from the coke," I am utterly at a loss to know why it should be so highly extolled, or to discover in what its merit consists. Of the improvement suggested by Mr. Shewin nothing certain is yet known, for it appears that at present it is quite in a crude state, and has not been sufficiently tried, to ascertain whether some greater inconvenience may not result from its use, than those which it is the object to avoid.

I cannot subscribe to the doctrine, that the economy of fuel must be greater in this than in other boilers. The theory of combustion is now too well known to lead us astray in this matter. Slow combustion and a small degree of heat, are not the most economical; for in this case it is known, that the carbon of the fuel is changed into carbonic oxide, which contains a considerable body of latent heat, whereas a rapid combustion changes it into carbonic acid, which is the most extreme change that fuel can undergo, and by which alone its complete combustion is effected. Another objection is, that it is only the internal surface of the boiler which is exposed to the fire. I have, I believe, seen every kind of boiler that has yet been used for hot water, and I am of opinion that no shape exceeds in efficiency the horseshoe, or saddle-boiler. It has been proved to be equally suitable for large or small apparatus, for I have seen as much as 1000 ft. of 4-inch pipe, heated well by one boiler, and some have come under my notice, which were heated by Mr. Fowler of Temple Bar, and appeared to me to be as near to perfection as could well be imagined. I have no doubt, however, that a great