oosnofM. 



on Table Monntaiii, at tlie Gape of Good 'Hope, ate addneei to 

 show that these, like the alleged attraetioii of doads by forests, aie 

 atbibntable to a reduction in Hie tranperatme of the air (p. iS). 



Chapter II — EffecU of ForesU on, the Bwmdity of the Ground, 51 



Sectios L — On iJie Wetness of Soads where these are over- 

 shadowed hy Trees, - 51 

 While the profuse evaporation from the tre^ thiongh the stomates 

 of the leaves is net overlooked, the wetness of toaAs is traced to the 

 efiect of the shadow occasioned by the trees preventing evaporadoa 

 from the overiludowpd portion of the road (p. 51) ; in illnstratioB 

 of which effect of thade are adduced experiments and observations 

 made at the Cape cf Good Hope (p. 52), and observatians on the 

 e&xt of shade on ponds in England (p. 33). 



Sbctiox IL — On the Desiceatum of Ground by DryUig Wind* 



being preoemted by the Shelter afforded by dumps of Trees, 55 

 Ulnstrationg are given of the eS.xi of shelter in anting evapota- 

 tjoo, and o( the extent to which even bosh may ae^ as a wind- 

 brake (p. 56). 



Sscnos TTT- — On the General PheTwmena of Evaporation from 



Fore^, 57 



There are given indications of evaporatim bdng retarded by forests 

 (p. 59), observations on the qnantity of ram arrested by leaves 

 made by Marclmll VaQIant (p. 61) and by M. Ma&iea (p. 62), 

 observations by the latter on the diSeroit qoanlities of water 

 evaporated in woods and in adjaerait open land (p. 63), and notices 

 of corresponding observations jnade by Kslra'(p. 64), with the eon- 

 douon from the whole that nnder the same meastire of rainfall the 

 soil of the forest retains notably more water than does oncovered 

 ground (p. 63). 



Section IV. — On the Moisture being attraeted from the Atmos- 

 phere, or otherwise retained in, the Ground by Vegelahle 

 Mould, - - 65 



U is stated how it may be seen that there is a greater qnaotify ol 

 moistnre in the soil of a forest than in the soil of open eonntiy 

 (p. 65) ; illostiations are given of the process whereby such nuns- 

 tore is absorbed (p. 65); the diSerence between iiaa asd the 

 deposit of dew is pranted out (g. 66); the property is stated to be 

 poBseEsed in a high degree by clay and by vegetable monld (p. 67); 

 the latter is shown to be a prodoet of forests, and a mode of dets- 

 mining the qoantity of it in the soil is described (p. 70), sad the 

 hnmns is shown to be liable to deetmipositioa whai exposed to the 

 nys of son, im&aded by herbage and tre^ (p. 71). 



