154 CALCAREOUS MANURES-PRACTICE. 



part of the process may be easily added to the foregoing— but it will very 

 rarely be required. 



If desired, the proportion of silicious and aluminous earth may be ascer- 

 tained, with enough truth for practical use, by stirring well these parts 

 (minutely divided) in a glass of water, and after letting it stand a minute, for 

 the sand to subside, pouring off the fluid into another glass. The sand 

 will be left, and the finely divided earth and clay pass off with the water, 

 and may be separately collected and dried on filtering paper, and weighed. 



For want of attention to the only safe guide, the chemical analysis of 

 marl, gross errors are often committed, and losses continually sustained. 

 By relying on the eye only, I have known marl, or rather a calcareous 

 sand, to be rejected as worthless, and thrown off at considerable cost of 

 labor, to uncover worse marl below, in which whole shells were visible ; and 

 on the contrary, earth has been taken for marl, and used as such, which 

 had no calcareous ingredient whatever. The best marls for profitable use 

 are generally such as show the fewest whole shells, or even large frag- 

 ments—and would be passed by unnoticed in some cases, or considered 

 only as barren sand, or equally worthless clay. But even if such mistakes 

 as these are avoided, every farmer using marl, without analyzing specimens 

 frequently and accurately, will incur much loss by applying it in quantities 

 either too great or too small. 



If marl reaches the surface, or " crops out," any where, it may be found 

 most easily by examining the beds of streams passing through the lowest 

 land, or deepest ravines. A few of the smallest particles of shells found 

 there will prove that the stream passes through marl somewhere above ; 

 and a careful examination continued towards the source, will scarcely fail 

 to discover where the bed lies. Its usual direction is horizontal, or very 

 little inclined ; and therefore if discovered any where along the sides of a 

 narrow valley, it may generally be found by digging on the opposite side, or 

 elsewhere not very distant at the same elevation on the hill-side ; and it is 

 always nearer the surface on swells, or the convex parts of the hill-side, than 

 where it retreats and forms hollows. In the more level parts of the coun- 

 try, the marl sometimes is very near the surface of the lowest land, and yet 

 is not visible any where. In such situations, particularly, a cheap and con- 

 venient auger may be used with much advantage in seai cuing for marl ; 

 and it is also useful to try the depth or quality of a bed, even when its sur- 

 face has been found. This tool may be made by welding a straight stem, 

 half an inch square and six or seven feet long, to a common screw auger 

 of about one inch and a half bore. If it has been so much worn as to be 

 useless as a carpenter's tool, it will serve for boring in earth) A cross-piece 

 for a handle should be fixed to slide over the stem,. and be fastened by a 

 small screw at different elevations, as most convenient. Other pieces n)ay 

 be added to the stem, attaclied by joints, so as to bore twelve or more feet 

 deep. Dr. Wm. 1. Cocke, formerly of Sussex, to wliom I am indebted for 

 this simple but useful tool, was enabled by its use to find a very valuable 

 bed of marl which was no where visible ^t the surface, and which he 

 used to great extent and advantage. 



Mr. Williams Carter, of Hanover, lias introduced a sunple and useful 

 improvement which greatly facilitates the use of the cheap and light auger 

 just described. When one or more additional joints are required, (fur bor- 

 ing to greater depth than seven or eight feet,) the process becomes much 

 more troublesome, because of the necessity for separating and re-uniting the 

 several joints every time the auger is drawn up to take offtlie earth, which 

 has to be done for every four or five inches of depth gained. This trouble 

 may be avoided by Mr. Carter's method. This is, to have a rough bench, 



