312 



JOUENAL OF UORTICULTUEK AND COTTAGE GAKDENEB. 



[ M»y 2, 1867. 



the pleasure of speaking thus of a publication, and every reader 

 of the volume will asBeut to our opinion of its merits. 



We recommend it especially to our gardening friends, not as 

 a foreteller of weather, but as an explainer of many of their 

 operations, and as a guide to much information which they are 

 continually needing. Thus, there are isothermal maps, show- 

 ing at a glance the temperatures of the air and soil to which a 

 plant is accustomed of which they know the native place. Every 

 chapter, however, contains explanations and facts, enabling the 

 gardener thoroughly to comprehend the reasons for many ope- 

 rations which he has been taught to adopt, and so to compre- 

 hend them constitutes enlightened practice. We have many 

 passages marked which deserve extract, but we mu-st be content 

 with the following : — 



" Rmliatinii from the Eiirfh. — The degree to which the temperatnre 

 falls tlepemlK ou the radiating and conducting powers of the surface 

 over which the thermometer is placed, being greater as the radiating 

 power is greater, and the conducting power less, and vice versa. 



" One of the most instructive examples illustrative of this subject 

 that could he given, is the result of Mr. Glaisher's observations on 

 the different temperatures of long and short grass. A thermometer 

 placed on long gi-ass was found to be on a mean 1.1^ lower than one 

 on short gi'ass, whilst the temperature of the soil under long grass was 

 1.1° higher than under short grass. The temperature was thus the 

 same amount in excess under the long gi-ass, as it was in defect over 

 it. Hence the difference of temperature over the long and the short 

 grass was entirely due to the greater quantity of heat conducted from 

 the soil to the top of the short grass, over that conducted to the top 

 of the long gi-ass, and not to any difference in the radiating powers of 

 the grasses. The experiments were extended, and it was found that 

 the temperatnre varied with every variation of length, fineness, and 

 closeness of texture of the blades of the gi-ass." 



" Dew-jmnt. — The ascertaining of the dew-point is of gi-eat prac- 

 tical importance, particularly to horticultmists. since it shows the 

 point near which the descent of the temperature of the air will be 

 an-ested during the night- For when the air has been cooled down by 

 radiation to this point, dew is deposited, and latent heat given out. 

 The amount of heat thus set free being great, the temperature of the 

 air is immediately raised. But as the cooling by radiation proceeds, 

 the air again falls to, or slightly under, the dew-point ; dew is now 

 again deposited, heat Uberated, and the temperature raised. The 

 same process continues to be repeated, and thus the temperatnre of 

 the air in contact with plants and other radiating surfaces may be 

 considered as gently oscillating about the dew-point. For if it rises 

 higher, the loss of heat by radiation speedily lowers it, and if it falls 

 lower by ever so little, the liberation of heat as the vapour is con- 

 densed into dew as speedily raises it. Thus, then, the dew-point de- i 

 termines the minimum temperature of the night. 



" This suggests an important practical use of the hygrometer. If 

 the dew-point is ascertained by it, the approach of low temperatures or 

 of frost may be foreseen and provided against. Thus, suppose on a I 

 fine clear spring day, towards evening, that the dry bulb was 50°, and 1 

 the wet 40° ; the dew-point at the time is, therefore, 20.4°, Frost on ; 

 the ground may then be predicted with certainty, and no time ought 

 to be lost in protecting such tender plants as may be exposed in the 

 open air at that season. If, on the other band, with a sky quite as 

 clear, the di7 bulb -was 50°, and the wet 47° ; the dew-point being 

 thus 43.8°, no frost need be apprehended. The raising or depressing 

 of the dew point during the night by a change of wind, is the only 

 cii-cumstanee that can happen to interfere with the predictions founded 

 on the hygi-ometer." 



A Practical Treatise on the Hybridisation and Cnllivation of 

 the Tviculor Felargoniunis. By Thoius Dixon, Gardener to 

 W. Blinkhorn, Esq.,W^aterdale, Sutton, St. Helens. 

 _ The title-page tells the truth — this iv a trustworthy, prac- 

 tical treatise, and we recommend every one who desires to raise 

 new varieties of these Pelargoniums, to send thirteen postage 

 stamps to Mr. Pixon, for a copy. We say " every one," be- 

 cause the directions are so full, and so explicit, that the most 

 inexperienced will readily understand how to proceed. There 

 are ample instructions arranged under the following beads : — 



" Ist, To secure the most suitable varieties for parent plants. 



" 2ud, That they should not he in an exhausted state for want of 

 rest. 



*' 8rd, That the plants should not be grown too luxuriantly by apply- 

 ing stimulating manures. 



" 4th, That the atmosphere of the house be dryish when the 

 anthers open, so that the pollen will not be caked together, and unfit 

 t i apply to the stigma. 



" 5th, That the seeds be kept neither too wet nor too di*y in the 

 seed-pan. 



*' 6th, That the young seedlings get strong before potting from the 

 seed -pan. 



*' 7th, That they do not damp off from being over-watered, kept too 

 close, or for want of heat, after they are potted from the seed-pan. 



" 8th, That the plants for hybridising be put under growing treat- 

 ment not later than the latter end of February-, or the beginning of 

 March, better sooner than later ; in fact, any time after the middle of 

 Januarv."' 



NOTES AND GLEANINGS. 



Her Ma.iesty has signified her intention of laying the first 

 stone of the Hall of Arts and Sciences on Monday, the 20th of 

 May. The contractors for the building, Messrs. Lucas Brothers, 

 are busily engaged in making preparations tor the ceremony. 

 The ground is being excavated some feet in depth, so as to 

 mark out the amphitheatrical form of the building, and the 

 excavation will be covered in with canvas to protect the specta- 

 tors of the ceremony from every contingency of weather. 



It is our painful duty to announce the death of the- 



Kev. Georoe Cbeere, of Papworth Hall, St. Ives, Huntingdon- 

 shire, which took place on the lOth of April. The deceased 

 gentleman was a member of the Floral Committee of the Royal 

 Horticultural Society, as well as one of the Vice-Presidents of 

 the International Horticultural Exhibition, and took a great 

 interest in horticulture, being himself an occasional exhibitor. 

 We last saw him, then apparently in full health and vigour, at 

 the Floral Committee meeting on the (jth of March, where he 

 had six pots of Mignonette, which were the admiration of 

 every one ; and on several other occasions he exhibited remark- 

 ably fine Anne Boleyn Pinks. 



WORK FOR THE WEEK. 



KITCHEN GARDEN. 



Asparntjns, in cutting, all the first shoots should be taken. 

 If one or two of the strongest stems are allowed to run up, the 

 other shoots from the same crown are placed at great disad- 

 vantage ; but ultimately some good shoots, but none of the 

 verv small ones, should be left to grow up. Where common 

 salt has been employed as manure, the Asparagus will be found 

 earlier and better ; the cutting, however, ought not to be con- 

 tinued in this case so late as is usually done under ordinary 

 circumstances. Broccoli, make a principal sowing of all the 

 late and spring sorts, such as Portsmouth, Sulphur, Dwarf 

 Late White, Knight's Protecting, Clarke's Early \\'hite, Wal- 

 cheren, and Somers' Particular Late 'Wbiite ; the latter will 

 form the last link between the late spring Broccoli and the 

 hand-glass Cauliflowers. Sow Clieriil, Chicory, and a bed of 

 Sweet Marjoram on a warm slope — this plant is much hardier 

 than Basil, and will do very well in this way ; also. Carrots for 

 drawing young, German Greens, Savoys, Eadislies, Lettuces, and 

 sucaessions of Peas and Beans. 



FRUIT GAR-DEN. 



It may be observed that portions of shoots of Apricots which 

 had been surrounded by the shreds in the preceding summer 

 have been more injured by the frost than the adjoining portions. 

 The shreds employed for fastening the sirmmer shoots should, 

 therefore, be of good quality, in order that very narrow strips 

 may suffice, and no more should be employed than is absolutely 

 required. Plenty of room should be allowed, and the leaves 

 should hang free, and not be bundled along with the shoots. 

 Walls are expensive, and every gardener ought to keep a good 

 face upon them as long as possible, by not driving nails farther 

 in than is necessary. For summer nailing it will generally be 

 sufficient that merely the point of the nail be inserted, just 

 enough to hold, but rarely farther than would render difficult 

 its removal by the finger and thumb. With regard to driving 

 nails in the face of the brick, that is quite inexcusable. Water 

 effectually all trees that require it. If only a little rain fall, 

 insufficient to reach the roots, so much the more will the trees 

 suffer on the return of dry weather, an expanded foliage being 

 induced, requiring an increased supply of moisture which the 

 roots are not in a condition to give, if judicious watering be 

 not attended to. 



FLOWER GARDEN. 



Of course, manuring and dressing will proceed in an orderly 

 way. High-dressed ground should be mowed at least once a-week 

 at this period, for a well-kept lawn is a most pleasing object- 

 Let the dressing of all herbaceous or mixed beds and borders be 

 finished without delay, and prepare stations where blanks exist 

 to receive Verbenas, Fuchsias, Heliotropes, Calceolarias, &c., 

 now in the course of hardening o3 for this purpose, and for 

 forming masses. Self-sown annuals, the Mimulus family, the. 



