No. 11. 



Irrigation. 



349 



the main and important ingredient, carbon- 

 ate of lime.* 



In some particular localities I have found 

 green-sand forming so large an ingredient 

 of this marl, that it must add a very import- 

 ant value to the marl as manure. And it is 

 most probable that deeper excavations will 

 show still richer and more abundant ex- 

 posures of green-sand mixed with the cal- 

 careous marl, than I have yet been able to 

 find. While I hold the green-sand to be of 

 inferior importance by far to the calcareous 

 ingredient, still it is certainly, as an addition 

 thereto, of very great agricultural value, 

 however little is understood of the cause 

 and manner of its remarkable and yet un- 

 certain fertilizing action. 



The dip, or degradation, of the surface of 

 the great calcareous bed, or its angle with 

 the horizon, is generally from north to south, 

 and does not differ greatly from the general 

 slope of the country, and the consequent 

 courses of the rivers ; but is greater than 

 either. This greater general dip of the 

 surface of the marl, or irregularity of sur 

 fece, is much more marked on the Santee 

 than on the Cooper, and on the Cooper than 

 on the Ashley and those rivers still further 

 south and west, passing through this region 

 And the entire body lies deeper below the 

 surface of the rivers as we proceed south- 

 westward, in any line parallel with the 

 sea-coast, with some exceptions from this 

 general rule, on and near the Savannah 

 — Ruffin's Agricultural Survey of S. C. 



For the Farmers' Cabinet. 



Irrigation. 



Mr. Editor, — It is said, that "Van Hei- 

 mont planted a willow which weighed 5 lbs., 

 in a pot containing 200 lbs. of earth. This 

 he watered for the space of five years, and 

 at the end of that time the tree was found 



* The marl of the Great Carolinian bed is not more 

 remarkable for uniformitj' of character throughout its 

 great extent, than for difference from all the marls of 

 Virginia, numerous and widely differing as are the va- 

 rieties of the latter. It is enough to say here, that the 

 marls of Virginia are generally much poorer than those 

 of the body described above, the bed is comparatively 

 very thin and limited in extent, and composed for the 

 greatest part of shells and their fragments of more re- 

 cent formation, (middle tertiary) in good preservation, 

 imbedded in a looser and softer earth, principally and 

 generally of sand. The many varieties of marls 

 known in Virginia, were described at length in a Re- 

 port to the Board of Agriculture of that State, giving 

 a full "description and account of the different kinds 

 of marls, and of the gypseous earth, of the tide water 

 region of Virginia," which forms part of the "Essay 

 on Calcareous Manures," commencing at page 194. 



to weigh 169|: lbs., while the earth in which 

 it had stood being dried as at first, was found 

 to have lost only two ounces. Here then, 

 was an increase of 164 lbs. weight, and yet 

 the food of the plant had been water only." 

 If then watering is attended with such 

 great results in the case of a tree, is it not 

 reasonable that in the case of herbage, it is 

 still more important 1 It is not by any 

 means, at this day contended, that the only 

 food of plants is water; but water generally 

 holds in solution minerals, which are food 

 for plants ; and it carries those dissolved 

 minerals to the roots of plants, exactly 

 where they are wanted. Land may have 

 all the necessary minerals and manure, in- 

 dispensable to plants, and yet in a dry sea- 

 son the grass won't grow; — how important 

 then is irrigation, if only to dissolve those 

 minerals. And where no running perma- 

 nent stream can be had, it would well repay 

 the farmer for digging an artificial pond at 

 some suitable place, where a considerable 

 body of water could, without much expense, 

 be collected and retained until the time of 

 need, and thus prevent the too rapid running 

 oft" of the rain water. Mr. Liebig, I think 

 it is, who says that in Germany, lands which 

 have formerly been nearly barren, have been 

 made, by irrigation, very productive. The 

 mode adopted in this country for watering 

 meadows, is considered by many as too ex- 

 pensive; they have consequently ploughed 

 up their meadows and do not water at all. 

 What the mode of watering is in Germany, 

 I do not know, but I would respectfully sug- 

 gest the use of a wheel mentioned by Dr. 

 Arnott, in his Elements of Physics, by 

 means of which, "streams are caused by 

 their own action, to lift a part of their water 

 into elevated reservoirs." For the purpose 

 of watering meadows, where the streams 

 lie high, a small portable wheel of this kind, 

 of about three feet diameter, would save the 

 labour of making a great many small chan- 

 nels. But where the water is situated low, 

 and is required to be raised a considerable 

 height, " a large water-wheel is placed so 

 that the stream may turn it ; and around its 

 circumference buckets are attached, to be 

 filled as they sweep along below, and to be 

 emptied into a reservoir as they pass above, 

 — or instead of buckets, the spokes of the 

 wheel are themselves made hollow and 

 curved, so that as their extremities dip into 

 the water at each revolution, they receive a 

 quantity of it, which runs along them as 

 Ihey rise, and is discharged into a reservoir 

 at the centre. These are called Persian 

 wheels, but they are in common use on the 

 banks of the Nile, and elsewhere." 



I would suggest the formation of agricul- 



