ON THE ADVANTAGES OF IRRIGATING GARDEN GROUNDS. 333 



surface of the ground. But if water thus given be not continued 

 regularly, injurious effects frequently follow ; for the roots of plants (as 

 I have shown in the Philosophical Transactions, in a paper upon the 

 causes which direct the roots *) extend themselves most rapidly wherever 

 they find proper moisture and food ; and if the surface alone be wetted, 

 the roots extend themselves superficially only, and the plants consequently 

 become more subject to injury from drought than they would have been 

 if no water had been given to them ; a circumstance which can scarcely 

 have escaped the notice of any observant gardener. When, on the con- 

 trary, the soil is irrigated in the manner above recommended, it is 

 wetted to a great depth ; and a single watering once in eight or ten 

 days is, in almost all cases, fully sufficient. 



I have found the advantage of being able to command, by the means 

 above-mentioned, abundant water at all seasons, and at very small expense, 

 so great, that I feel confident that a market gardener could, in many 

 cases, afford to give as much rent for one acre as he could under ordinary 

 circumstances give for two acres ; for he would not only be able generally 

 to command more abundant crops, but, by possessing exclusive advantages, 

 he would often, in unfavourable seasons, be enabled to raise abundant 

 crops of articles which, in such seasons, usually take a very high price. 

 In selecting the site of a garden the advantage of irrigating it, by the 

 means above-mentioned, may very frequently be obtained ; and the num- 

 ber of gardens above which a small tank or pond might be easily made 

 is probably much greater than at a first view will be supposed. 



It may be objected that excess of rain is more often injurious in the 

 climate of England than drought ; but in wet seasons plants suffer owing 

 to want of light, and generally of warmth ; and I feel confident that if 

 the same quantity of rain, which the soil receives in our wettest summer, 

 were to fall only between the hours of nine in the evening and three in 

 the following morning, and the sun were to shine brightly and warmly 

 through the whole of the days, no injurious effects would follow ; and 

 every experienced gardener knows with what luxuriance and rapidity 

 plants of every species grow in hot and bright weather, after the ground 

 has been drenched with water by thunder-storms. 



* See above, p. 157. 



