92 



NEW ENGLAND FARMER, 



Fes, 



ture ; the true value of this department of scien- 1 

 tific knowledge cannot be estimated, since much 

 more is now known than has yet been .generally 

 and skilfully applied ; and, again, there is much 

 of agricultural chemistry which is yet in so vague \ 

 and uncertain a state as to be almost, if not quite 

 worthless, as far as practical farming is concerned. 



If it Avere true, as some have the hardihood to 

 assert, that no practical good, as far as crops and 

 ])rofits are concerned, arises from scientific re- 

 search in this department, yet its benefits upon 

 the mind of the fanner would be incalculable, as 

 it raises his thoughts to the contemplation of the 

 laws of nature, giving him one of the most stable 

 of all pleasures, and in health of mind, the crown 

 of "green old age." 



Assuming that every farmer is both a practical 

 chemist and geologist, since the most common 

 duties of the farm require a knowledge of these 

 sciences, I wish to call attention to the chemis- 

 try and geology of the surface stratification. 



For the sake of simplicity in the treatment of 

 the subject, I will divide the varieties of soil into 

 three classes, namely, 1, mechanical ; 2, chemical ; 

 3, vegetable. This general classification may strike 

 the geological I'eader as novel and perhaps inade- 

 quate, but for the ordinary discussions of practi- 

 cal men. I think it will b2 found not inappropri- 

 ate, if we boar in mind that the terms used are 

 not intended to indicate by what agency the ma- 

 tjrials of which the soils are composed Avcre 

 brought into their present positions, but simply 

 to express the present condition of the soil itself. 

 Thus, by mechanical, I would designate all earths 

 v;hich bear evidence of not having undergone any 

 great chemical or vegetable change since being 

 deposited in their present position ; that is, the 

 tnixture of the different materials of which they 

 are composed is simply a mechanical one ; by 

 chemical, all that indicate by their strata and com- 

 jjositlon that some important change in their qual- 

 ities has taken place since their deposition ; and 

 by the last term, all that are principally made up 

 or' vegetable matter. 



The first of these formations, or classes of for- 

 mations, to which I give the name mechanical, 

 may be found in nearly all positions, though per- 

 haps oftener in low than high grounds. Under 

 this head will be classed moraines, sand-hills and 

 bars, ancient river-beds, and all such surface stra- 

 ta as bear evidence of having been deposited by 

 some violent mechanical action. 



Upon examination of the strata of this class, we 

 find tliem sometimes composed of regular layers 

 of material, which is not always coarsely divided, 

 but yet is never thoroughly, chemically united ; 

 others have na*regular layers, but seem to be 

 composed of confused 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 Isngthy 

 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^frcsh 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 &om which were depogsited a large 

 portion of the surface formations of the eastern 

 part of NcAV England, are supposed to be analo- 

 gous to the oceanic cm-rents of the present, and 

 probably arose from the same cau-ses, namely, 

 evaporation, difi^erence of tempei'ature of the po- 

 lar and equatorial regions, and the earth's rotary 

 motion. 



The currei^ts of the ocean are, without doubt, 

 constant, considered as a whole j in other words, 

 there ahvays exists a series of currents and coun- 

 ter cun-ents, those from the poles moving south- 

 westerly, and those from the equator north-easter- 

 ly, of the northern hemisphere ; for the southern 

 hemisphere, the reverse is true. The existence of 

 these cun-ents is tlms accounted for. The velocity 

 of the surface of the earth at the equator is about 

 one thousand miles per hour, towards the cast ; 

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

 hundred and fifty miles per hour ; therefore, wa- 

 ter at the equator has a velocity of one thousand 

 miles per hour, and water at 45° but seven hun- 

 dred 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 per hour, lessened 

 only by friction ; hence, when it amves at 45°, 

 where the surface motion of the earth is but seven 

 hundred and fifty miles per horn*, it will have an 

 easterly motion exceeding in rapidity that of the 

 earth's surface by two himdred and fifty miles per 

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

 excess is great ; this excess of velocity being com- 

 bined with the northerly direction gives the cur- m 

 rents their north-easterly course. The same rca- ■ 

 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 arc examples of the last, Balloon- 

 ists take advantage of this same principle, and 

 found upon it their theories of easterly aerial cur- 

 rents, in Avhich they think they may be able to 

 cross the Atlantic. The cfl"ects of these currents 

 arc abrasion and drift. 



The action of a cuiTcnt of water sweeping over 

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

 high points and deposit it in valleys ; but its ef- 

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

 earth removed, than the solid rock is attacked, 

 and in its turn carried down to the valleys. This 

 mechanical action upon the rocks, together with 

 the chemical decomposition that is constantly 

 taking place, is called detrition : the resulting de- 

 posit is called drift. 



Currents of air produce the same results as 

 cmTents of water, aiid though the action of the 

 wind is much less important, it is still so great as 

 to be well worth careful consideration. The aque- 

 ous cuiTents cease their action before the land be- 

 comes inhabited, but the aerial ones are always at 

 work. 



The eff'ect 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 abraF--icn, its action 

 is much more complicated and difficult to 



