336 



Irrigation 



Vol. It 



that marl is often produced by the decuH posi- 

 tion of silex or flint." 



The late Dr. H. Seybert, was, it is sup- 

 posed, the first who analysed the green saad 

 or marlof New Jersey. He found in a speci- 

 men from Rancocus creek, Burlington Co. 



49.83 

 6.00 

 1.83 



10.12 



9.80 

 21..53- 



-99.11 



Sile.x, 



Alumina, 



Magnesia, 



Potash, - 



Water, - 



Protoxide of Iron, 



With a trace of Chrome. 

 By the above it will be perceived thai there 

 is no lime in its composition. Professor Ro- 

 gers who has made a geological survey of 

 New Jersey which is before the public, fur- 

 nishes the analysis of various specimens from 

 different localities, accompanied by many ui- 

 teresting practical remarks in regard to its ap- 

 plication to the soil, and its effects on vegeta- 

 tion, which have been of great value to the 

 farmers of that state. The result of his analysis 

 don't differ widely from the above. Some- 

 times more or less carbonate of lime was pre- 

 sent, and the other component parts varied 

 their proportions; but in all cases where it 

 has been applied to the soil as a manure, the 

 effect produced by it, was in due proportion 

 to the predominance of potash in its composi- 

 tion, without reference to the other ingredi- 

 ents which are in combination with it. "^This 

 article is not found in Pennsylvania, nor is it 

 known to the writer to exist in any part of 

 our country, except in the sandy, alluvial 

 soil of New Jersey, Delaware and Maryland, 

 and perhaps the alluvial parts of the states 

 farther South. 



Extensive preparations are said to be ma- 

 king to use the green sand or marl in Dela- 

 ware and Maryland, where you have nume- 

 rt :s subscribers, who would feel under great 

 obligations to any ofyourcorrespondentlwho 

 would enlighten their path in the practical 

 use of this comparatively new and valuable 

 manure. T 



3«Eanagrement of ©rass Siands. 



IKRIGAT10.\. 



The fertilizing effect of water on the earth 

 is one of those natural phenomena which 

 every where force themselves upon the at- 

 tention of mankind, \7ater is seen to be es- 

 sential to vegetable life. In those climates 

 where evaporation is the greatest, nature has 

 generally provided the most plentiful supply 

 of this fluid, in rains and dews. But the rams 

 oflen occurring at a particular season of the 

 year, are insufficient for the life and nourish- 

 ment of useful plants during the remainder, 

 and the art of the irrigator is'therefore neces- 

 sary to produce fertility. Without the arti- 

 ficial conveyance and djstribuuon of water, 



some of the most fertile countries in the 

 world could not have supported their inhabi- 

 tants ; and tlie earliest husbandmen accord- 

 ingly knew and pnictised the watering of 

 lands as an art. In Egypt, where the great 

 inundation of the Nile soon taught the inhabi- 

 tants the value and uses of irrigation, this art 

 is known to have been practised on a scale of 

 surpassing magnitude; and the canals and 

 vast artificial lakesof that celebrated people, 

 though less enduring^ are more praiseworthy 

 monuments of their genius, than all the tem- 

 ples and cemeteries with which they have 

 covered their country. From the valley of 

 the Nile, it is to be believed, the knowledge 

 of the art would be extended to many cou'n- 

 tries. To the Greeks and the Romans it was 

 well known, and the rustic writings of the lat- 

 ter abound with allusions and rules relating 

 to the watering of land. Without water col- 

 lected by art, rice, which furnishes food to 

 the greater part of the human race, could not 

 be cultivated; and over the vast regions of 

 Southern Asia, accordingly, the watering of 

 land from rivers, brooks, lakes, and wells, is a 

 labor essential to the support of the inhabi- 

 tants. In all the southern countries of Eu- 

 rope, the art is more or less practised. It is 

 there that the water is conveyed in little 

 channels to the corn fields, to the vineyards, 

 and to the olive-trees. The conducting of it 

 from the rivers and canals, and measuring it 

 out in determined quantities, form, in several 

 parts of Italy, a nice part of the science of en- 

 gineering. In Piedmont, and the whole val- 

 ley of the Po, the water is frequently paid for 

 by the hour, and the utmost care is bestowed 

 in economising so precious a substance. 



The main object of irrigation, however, in 

 all tlie intertropical countries, and in the 

 warmer parts of the temperate zones, seems 

 merely to be to convey to the ground that 

 quantity of water which is necessary for the 

 growth and nourishishment of the plants to 

 be produced. Sometimes, as in the case of 

 rice, the earth must be saturated for success- 

 ive months, and, in others, merely watered at 

 intervals, during the periods of greatest evap- 

 oration. In all these cases the main purpose 

 is the same, namely, to supply the deficiency 

 of vvater in the soil ; and this creates a great 

 distinction between that species of irrigation 

 which has been described as called for by the 

 wants of man over so great a part of the 

 globe, and that to which we apply the term 

 watered meadow. 



In the latter case, the purpose is not to sup- 

 ply the deficiency of water in the soil, for the 

 water is conveyed over the surface at those 

 times, namely the months of winter, when 

 there is an excess, and not a (leficiency of 

 moisture. Nay, it is held necessary in every 

 well-formed watered meadow, to dxain the 



