Review of Loudon^ s Gardener's Magazine. 181 



REVIEWS. 



Art. 1. The Gardener s Magazine, and, Register of Rural and 

 Domestic Improvement. Conducted by J. C. Loudon, F. 

 L. S., H. S., &c. In monthly 8vo. numbers, Is. 6d. each. 

 No. LXX, for January. 



The first article is upon " the relative temperature of the earth, 

 under surfaces covered with a vegetable coat, and under surfaces 

 preserved bare; with a table of observations." 



From these observations, (a table of which is given,) which were 

 accurately made, it appears that with one or two exceptions, the 

 earth beneath the surface of grass, was uniforjiily of a higher tem- 

 perature than that under a bare surface, or that not covered with 

 vegetation. The following are the author's remarks: — 



"A careful examination of the table will present some interesting rela- 

 tions between the aerial temperature, the state of the weaiher, &c., and 

 the teniperatiu'es of the siu'laces of gratis and earth. They are hardly 

 sufficient, however, to enable it to be pronounced with certainty to what 

 cai se the difference of teniperatm-e is to be assigned ; whether to some 

 result of the principle of vegetable life, altogether distinct from the mere 

 phenomena of heat ; to chemical or other forces, j)ut in motion by the 

 assimilative powers of the plants; or to the simple effects of varying 

 powers of absorption and radiation. To the latter of these conclusions I 

 myself incline ; but one most interesting, and, I believe, novel, fact is thus 

 established ; namely, that the surface of our earth is considerably affected, 

 as to its temperature, by the vegetation that subsists upon it. Its tempera- 

 ture is proved to be increased by this covering; and we cannot fail to 

 recognize in this one of those innumerable and ever wondrous adaptations 

 by which the Author of natine has most fitted our system to the living 

 beings it is destined to support." 



The object of these observations was, to determine how far it 

 was advantageous, or otherwise, to cover the surface of vine and 

 peach borders with a clothing of turf. And the author's conclusions, 

 though at variance with the opinions of cultivators, seem quite 

 rational, and are deserving of particular notice ; we commend tliem 

 to the attention of our readers : — 



"The opinion of working gardeners is usually, I believe, unfavorable 

 to this, under the impression that the grass makes the soil beneath cold 

 and damp. The table shows that this view is unfounded, and that a great 

 advantage may be expected from the covering, both by increase of tem- 

 perature, and the preservation of a mo'e equable degree of moisture. 

 The advantage, in point of aj)pearance, of a vine or peach border, clothed 

 with velvety tin-f, over one bare and brown, is sufficiently obvious. I be- 

 lieve it is admitted, that plants or crops should never be grown on such 

 borders; but the amount of vegetable nutriment abstracted from the soil 

 by a short turf kept close is exceedingly small : and, where borders are 

 made very rich, they should be covered with 3 in. of sharp sand, and 



