JOUBNAL OF HORTICULTURE AND COTTAGE G.OtDENEE. 



[ Joimlr;- 4, 1872. 



of eom-ae, impossible to eoujectme. Some idea of the number 

 of Pines grown may be formed from the fact that Mr. Gilbert 

 is supposed to have a Piiie ready for table whenever one is 

 required. 



We will not enter largely iuto the vegetahle-forcmg depart- 

 ment, though heavy supplies are required and jiroduced, and 

 that, too, of excellent quaUty. For instance, of Asparagus 

 there are eleven Ughts, affording gathermgs from November 

 until it is obtained from the open ground, whilst of Mushrooms 

 the production, iu abimdance and excellence, is remai-kable ; 

 indeed Mushrooms are quite a speciality with Mr. Gilbert, and 

 he obtains them at all seasons with certainty and ease iu a 

 weU-coustructed liouse with beds ou arches, under which Ehu- 

 barb and Sea-kale are forced, and Endive brought on and 

 hlauched. The mode of cultivation which Mr. Gilbert pur- 

 sues was thus described by himself iu one of our former 

 volumes : — 



" I procure two cartloads of good fresh stable manure, and shake 

 out the longest of the straw. I am not, however, verj- particular 

 about this. Then it is turned over in the open air once or twice 

 to get rid of the rank steam. When this is gone the dung is 

 taken into one of the sheds at the back of the houses, and about 

 four barrowfuls of ordinary fresh soU mixed with it. The bed 

 is then made up on the floor of the shed to a depth of about 

 12 inches, pressed rather firmly, and spawned when at a tempe- 

 ratm-e of between 75° and 80°. A covering of about 1 inch of 

 good strong loam in a rather rough state is then added, and 

 beaten level with the spade. By using heavy loam as a covering, 

 the Mushrooms produced are of a much more solid character 

 than where light sifted soil is used; they are, consequently, 

 more valuable, commanding a far higher price in the market. 

 The whole is then covered up with at least 9 inches of straw or 

 long litter. 



" I never use any fire heat, as I consider that a piece of use- 

 less extravagance. Better Mushrooms can be gi-own without 

 fire heat than with it, and a continuous supply kept up through- 

 out the coldest winters. Then, if it is so, why should our em- 

 ployers be put to so much expense in erecting and heating grand 

 dungeons for this dainty, which can be so easily cultivated with- 

 out their aid ? " 



Three ridge beds out of doors have just been spawned, and 

 three more are shortly to be made, so that there is eveiy pro- 

 spect of the ample supply of Mushrooms being continued 

 throughout this as it has been in past years. In one of the 

 outside slips is a very cheaply formed and useful pit for 

 Carrots, Radishes, and new Potatoes. Instead of glazed sashes 

 the glass slides upwards and downwards in grooves, m the 

 same way as iu some veiy economical protectors which Mr. 

 Gilbert has had made as a substitute for hand-glasses. The 

 latter are of the best inch deal, thiice coated with x^aiut, and, 

 glass and labour included, cost but .3s. 6d. each. There can be 

 no doubt that as protectors they will prove more effective than 

 hand-glasses, more durable, and cheaiJer m the long iiui as 

 well as in their first cost. With regard to the houses, it should 

 be added that there are but three boUers, the whole of the 

 vineries and peacheries being heated by one of Weeks's tubular 

 boOers, with a spare one iu case of accident, and some of the 

 smaller house ny a saddle boiler. 



In the kitchen garden compartments, of which there are six, 

 enclosed by 12-feet walls, with 16-feet borders, are all the usual 

 crops in excellent condition, and nothing could be better than 

 the condition of the trees on the walls — Pears, Peaches, Necta- 

 rines, Apricots, and Figs. The first-named are horizontally 

 trained, in stages about 18 inches apart, and consist of a selec- 

 tion of the best kinds, ripening in succession ; and among the 

 Peaches are several twenty-three years old, lifted and replanted 

 last year, and looking none the worse of the operation. In 

 one of the borders Potatoes were being planted for early use, 

 the kinds being Coldstream Early, and Paterson's Victoria, 

 which Mr. Gilbert prefers to kidney varieties ; in another bor- 

 der is an excellent stock of Snow's Winter White Broccoli, 

 sowm at the end of March, to succeed Waleheren, just over; 

 and in a third a very fine stock of Brussels Sprouts, ranging 

 from 3 feet high, with the stems densely set with fine large 

 sprouts. These were the result of three seasons' selection, but 

 Mr. Gilbert thinks a further selection uecessaiy to render the 

 strain permanent. Extensive quarters of Gooseberries, well- 

 managed pyramid Pears, and all the ordinary kitchen-garden 

 crops are excellently represented. We have now only to add 

 that the fruit -room, root-stores, and the other requisite stnic- 

 tiu-es are conveniently and well arranged ; that in the young 

 men's rooms the convenience and comfort of the mmates have 

 been duly attended to; and lastly, that the order, neatness, and 



ability with which everything is managed, reflect the greatest 

 credit on Mr. Gilbert, whom we have long known as one of the 

 best gardeners in this countiy. 



HEATING BY HOT WATER. 



NoTWiXHSTAXDiNG all the elaborate essays that have from 

 time to time appeared in the horticultural press on heating 

 hothouses v.-ith hot water — not to say anything of the stin'iug 

 controversies that have taken place on the subject — we have 

 the best reasons for belie'i-ing that many wliom the matter 

 intimately concerns have still but veiy vague and enoneous 

 ideas regarding the principles upon wliich the proper adjust- 

 ment of hot-water boilers and pipes depends. And from some 

 cause or other, it is a notion very prevalent that the easiest 

 and shortest way to get deeply immersed iu the disagreeable 

 and undefined difiiculty figuratively tenned " hot-water," is to 

 plunge iuto this heating question, in which are involved 

 furnaces, boilers, pipes, fire, and water, besides that un- 

 fortunate being who has to control the elements and condi- 

 tions of combustion so as to have half-a-dozen thermometer- 

 needles in as many hothouses standing at certain hair-like 

 marks at half-a-dozen different times iu the four-and-twenty 

 houi'S. 



It is our belief that, if those who have to do with fixing 

 pipes and boOers were to make themselves acquainted with the 

 effects of heat and the power of gravitation on water, it would 

 be next to impossible to commit the blunders, and resort to 

 the unnecessaiy and expensive precautionary measures, one 

 so often meets with and has to deal with. It is no part of our 

 intention to pretend to deal with that imponderable and power- 

 ful agent called by men of science caloric, but which we shall 

 call heat — h;vi3othetically regarded as a subtle fluid, the particles 

 of which are to each other repellent, but attractive to all sub- 

 stances, though iu various degrees. But the effect of heat 

 upon water, an element composed of minute and distinct par- 

 ticles that are supposed not to have the quality or power of 

 transmitting heat the one to the other, as in the case of solid 

 bodies, is one of tlie matters concerning which some knowledge 

 is indispensable in the case of all who have anything to do 

 with heating by means of heated water circulating iu pipes. 



The particles of which water consists, it need scarcely be 

 said, have a capacity for heat from different sources, but most 

 manifestly so to us in this case from combustion on the fire. 

 Now the expansion of bodies is one of the most universal 

 effects of increasing their heat. This exjjansion takes place to 

 a greater degi'ee in some bodies than in others. Liqnids 

 expand much more by the same increase of heat than solid 

 bodies, and air more than either. With the expansion of the 

 individual particles of water, their specific gravity becomes 

 less; in other words, they become hghter in proportion to 

 their size. Here lies the whole secret of hot-water circulation 

 in pipes and boilers, and the well-known law which should 

 regulate theh relative positions the one to the other. The 

 heated particles of water bound upwards, and, as " Nature 

 abhors a vacuum," then- place is taken up by a rash of colder 

 and heavier pai'ticles. It is of very little practical use to cavil 

 about the question as to whether heat or the greater specific 

 gi-a\ity of the cold water which jostles up the warmer and 

 lighter plays the gi-eatest part iu sending up and away the 

 stream of hot water. Both have a hand in it, no doubt. This 

 influence of heat upon water can be very manifestly shown by 

 filling a tumbler with cold water, and mixing with it some 

 coloured particles of matter, and then immersing the tumbler 

 m a vessel filled with hot water. It \\-ill at once be seen, by the 

 motion of the particles of coloui'ed matter, that at the sides 

 of the tumbler there is an upward current of heated, and in 

 the centre a downwai'd current of colder, water. And this 

 goes on until the whole is of the same temperature. A glass 

 of warm water immersed in cold has the current reversed in 

 its comse — upwards iu the centre, and do^^•nwards at the sides, 

 where the water is being cooled. Here we have the whole 

 secret of the motion and course of heated water iu the boiler 

 and pipes of a i^roperly-adjusted heatuig-apparatus. And one 

 woiild suppose that the sunple understanding of tliis would 

 prevent any from making mistakes. Yet, strange to say, many 

 who undertake hothouse-building are entirely ignorant of these 

 simple and well-established facts. 



Wherever the heat generated by combustion in the furnace 

 acts most directly and powerfully, from that surface bound 

 upwards the particles of water, and to that spot, simultanc- 



