Peacock : The Soil Stoj'ehoiise. 



227 



produce grand effects. Soils six feet in depth are not uncommon 

 in wind-sheltered spots. Allowing- the average time, five inches 

 as the growth of 40 years, 580 years would make such a soil de 

 novo. From a few inches to two feet is the depth of soils, 

 speaking generally. The worms pile up the earth from below^ 

 ground around, and finally above all objects they cannot remove. 

 This action lets them sink into the soil by the force of gravity, as 

 the earth is removed from below. The double movement of 

 sinking and burial is so complicated, that only a third of the 

 motion downwards can be regarded as directly caused by 

 gravity. In pasture and meadow soil the burial is so steady 

 and continuous that it can be easily watched during the lifetime 

 of an ordinary individual. A round pebble, three inches in 

 diameter, disappears below the surface of rich pasture, and is 

 grassed over in 25 years. In very rich feeding land, with a large 

 supply of worms (60,000 to the acre at least), 18 years is all the 

 time that is required. The same gradual sinking goes on at 

 a uniform rate after the object is lost to view, till it reaches the 

 bottom of the humic earth, and comes to rest on the rock bed, 

 be it sand, clay, or the broken fragments of a stony bed. 



Tilth, unlike pasture, from being constantly ploughed up has 

 its upper levels mixed over and over again. It is rarely found 

 to contain much of interest. The work of burial cannot go 

 forward with the share ever revealing what lies between the 

 surface and the plough-sole, as it is technically called. It is 

 only a question of time in shallow soils, where the plough-sole 

 frequently catches the mother rock, before any object of interest 

 is turned out on the surface, and the ploughman views and 

 appropriates it. The exceptional cases are deep, arable soils 

 like silt, in which the share only enters the upper portion of the 

 humic earth. No burial during annual cultivation can still be 

 going on in such deep soils, but whatever was safely hidden 

 away below the plough-sole line before the soil was first tilled 

 is still there. 



Where old pasture and meadow, or deep arable soils, such as 

 we find round our villages, are opened for drainage or any other 

 purpose, a sharp watch should be kept on the line between the 

 black soil and its lighter coloured mother rock. Speaking 

 generally, little of interest for the antiquary or historian will 

 be found in the soil itself, where for the student of agriculture 

 as a science there is everything to learn. The methods and 

 periods at which the turf has been dressed to make it more 

 fruitful, will be exhibited at a less or greater depth according to 



1904 August I. 



