THE FARMER'S MAGAZINE. 



4i3 



Upon examination of the strata of this class, we 

 find them sometimes composed of regular layers 

 of material, which is not always coarsely divided, 

 but yet is never thoroughly, chemically united; 

 others have no regular layers, but seem to be 

 composed of confui^ed masses of gravel, sand, and 

 clay, which are not intimately united, nor in any 

 manner definitely divided ; here is a bed or layer 

 of gravel — it extends a few feet, and abruptly ter- 

 minates in a bed of clay, or perhaps gradually 

 growing thinner and thinner, disappears between 

 layers of clay and sand; again, we find strata of 

 almost pure sand. I cannot enter into a lengthy 

 explanation of the causes of these various phe- 

 nomena, but will briefly state them ; thus, when 

 the layers are comparatively regular, they are sup- 

 posed to have been deposited from running water, 

 either fresh or salt. The irregular stratification, 

 which in fact covers a large portion of the eastern 

 part of Massachusetts, is undoubtedly owing to 

 glacial action, as it occurs in ice-bearing currents, 

 while the occurrence of sand-hills is generally as- 

 signed to the action of the wind. 



The currents from which were deposited a large 

 portion of the surface formations of the eastern 

 part of New England, are supposed to be analo- 

 gous to the oceanic currents of the present, and 

 probably arose from the same causes, namely, 

 evaporation, difference of temperature of the polar 

 and equatorial regions, and the earth's rotary motion. 



The currents of the ocean are, without doubt, 

 constant, considered as a whole ; in other words, 

 there always exists a series of currents and counter 

 currents, those from the poles moving south- 

 westerly, and those from the equator north-easterly, 

 of the northern hemisphere ; for the southern 

 hemisphere, the reverse is true. The existence of 

 these currents is thus accounted for. The velocity 

 of the surface of the earth at the equator is about 

 one thousand miles per hour, towards the east : 

 while at 45'' north or south latitude, it is but seven 

 hundred and fifty miles per hour ; therefore, water 

 at the equator has a velocity of one thousand miles 

 per hour, and water at 45 degs. but seven hundred 

 and fifty miles per hour ; now, if, from any cause, 

 a body of water moves from the equator towards 

 the north, it will still retain its easterly motion of 

 one thousand miles jter hour, lessened only by 

 friction ; hence, when it arrives at 45 deg., where 

 the surface motion of the earth is but seven hundred 

 and fifty miles per hour, it will have an easterly 

 motion exceeding in rapidity that of the earth's 

 surface by two hundred and fifty miles per hour, 

 if it were not reduced by friction; as it is, the ex- 

 cess is great; this excess of velocity being com- 

 bined with the northerly direction gives the cur- 

 rents their north-easterly course. The same rea- 

 soning applied to currents flowing from the north 

 pole to the equator, will show why all such have a 

 south-westerly direction. The gulf stream is an 

 example of the first, and the currents which bring 

 down polar ice are examples of the last. Balloon- 

 ists take advantage of this same principle, and found 

 upon it their theories of easterly aiirial currents, in 

 which they think they may be able to cross the 

 Atlantic. The effects of these currents are abrasion 

 and drift. 



The action of a current of water sweeping over 

 the surface is, first, to remove all loose earth from 

 high points and deposit it in valleys; but its effect 

 does not end here, for no sooner is the loose earht 

 removed than the solid rock is attacked, and in 

 its turn carried down to the valleys. This mecha- 

 nical action upon the rocks, together with the 

 chemical decomposition that is constantly taking 

 place, is called detrition ; the resulting deposit is 

 called drift. 



Currents of air produce the same results as cur- 

 rents of water, and though the action of the wind 

 is much less important, it is still so great as to be 

 well worth careful consideration. The aqueous cur- 

 rents cease their action before the land becomes 

 inhabited, but the atirial ones are always at work. 



The effect of abrasion upon the surface is per- 

 fectly obvious ; it can leave nothing but a barren 

 and hard strata wherever it takes place. Though 

 drift is but the counterpart of abrasion, its action 

 is much more complicated and difficult to un- 

 derstand. Its effects are commonly just the oppo- 

 site; for wherever drift accumulates, there we may 

 he nearly sure of finding good land. In New 

 England, wherever a soil is evidently composed of 

 drift from an oceanic current, it is easy to state its 

 chemical composition, as originally deposited; we 

 have only to examine the exposed rocks lying in a 

 direction north-easterly from it; their nature must 

 of necessity determine the nature of the soil in 

 question. It should be remembered, that, in the 

 examination of soils, this is to be considered but as 

 a general truth, and that there are so many modi- 

 fying causes that this knowledge alone will not 

 enable one to detei'mine with any degree of accu- 

 racy the present chemical nature of the soil. 



One of the most important considerations for the 

 New England agriculturists, and one in which 

 almost every farmer is directly interested, is that of 

 river and lake deposits ; these consist of not only 

 large amounts of finely granulated mineral, but also 

 vast quantities of vegetable matter. The extreme 

 richness of such deposits must be acknowledged 

 by every one who considers the following fact : 

 first, the minerals of which they are composed are 

 finely and intimately mixed ; second, the finely 

 divided minerals are not only carbonized, but are 

 brought in connection with particles of carbon and 

 decaying vegetable matter, or humus ; and lastly, 

 the entire mass is more or less impregnated with 

 ammonia. Although it is impossible to conceive 

 of a richer soil than this, yet it is probable that 

 there is no class so universally neglected and de- 

 spised. In scientific classification, soils formed of 

 these deposits are called fluviatile and lacustrine ; 

 the farmer turns them oflF with the not very flatter- 

 ing title of swamp or mud hole. 



As an example of the magnitude of these de- 

 posits, the following may be interesting. The area 

 of the delta of the Mississippi is 13,600 square 

 miles ; the average depth of dejjosit is 528 feet, 

 and it has been estimated that the river annually 

 deposits thirty- seven hundred millions of cubic 

 feet! This at first thought seems large ; but even 

 at this rate, the venerable father of rivers must 

 have diligently laboured for sixty-seven thousand 

 years. — New England Farmer. 



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