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Continent of Europe, orchards under grass are of frequent occur- 

 rence. In Australia, where climatic conditions are totally different, 

 the old methods have likewise been tried and have failed. Vines 

 and fruit trees, to be profitable in this climate, must not only be kept 

 scrupulously clean, but the surface of the soil must be stirred at 

 frequent intervals. 



Some growers rest satisfied after they have r-idden the ground 

 of the growth of thirsty weeds whose roots rob the vines and trees 

 of their full share of the nutriment and the moisture available. 



This, however, is only half of what should be done in a country 

 like this ; clean cultivation is not all that summer cultivation 

 implies : it is only part of it. Summer cultivation acts besides in a 

 variety of other ways ; it maintains the soil in a condition favour- 

 able to the growth of the roots of the plants ; it retains moisture 

 in the ground, and it also leaves it in the most favourable condition 

 for absorbing more moisture from the atmosphere ; by opening up 

 the soil it promotes its sweetening through the action of the 

 atmosphere on the particles of the soil. 



The mechanism by which moisture is retained in the soil by 

 means of summer cultivation may thus be exemplified, for the sake of 

 impressing on the mind its capital importance so far as the pursuit 

 of fruit-growing is concerned. It is a fact of every day observation 

 that a brick wall built on moist ground is always more or less 

 damp, and sometimes covered with a growth of green mould to a 

 height which varies from a few inches to a few feet above the 

 surface ; the same thing noticeable on stakes driven into the ground, 

 as well as on old trunks of dead trees. The moisture is sucked up 

 from below by capillary attraction. It is also owing to capillary 

 attraction that the oil in the lamp rises in the wick, and that little 

 hairlike vaccine tubes, for instance, can be filled up with calf lymph. 

 Similarly, in a hard and set soil, moisture is often drawn up from a 

 depth of several feet, and precisely as the oil burns, when the lamp 

 is lighted, on the end of the wick exposed to the air, so the water 

 drawn up from below is evaporated when it reaches the crust of the 

 soil heated by the sun and fanned by the wind. As fast as the oil 

 burns more oil is drawn up from the lamp to replace it ; so in soil, 

 as the water is evaporated on the surface more water from below 

 rises to replace it, and the hotter the sun the more exposed the 

 surface to the action of the wind, and also the harder and more 

 compact the crust of the soil, the more active is the evaporation, 

 and, consequently, the drying- up of the soil, until at last it becomes 

 as " dry as brick." 



The best method, therefore, of preventing that wasteful escape 

 of moisture from the ground is by loosening and breaking up the 

 crust of the soil ; by so doing the capillary attraction is, for a time, 

 destroyed close to the surface, although it goes on without check 

 a little deeper down; water continues, without sensible interrup- 

 tion, to be drawn up all the same from the subsoil, but, owing to 

 the fact that it is no longer sucked up to the surface, where it would 



