314 
Annual Report of the 
The surface is usuall} r strewn with bowlders, while cobble-stones 
and gravel mingle with the soil, though not to an extent that 
would justify the term gravelly. 
This soil works with somewhat more dificulty than the last, but 
is strong and enduring, and will improve rather than otherwise with 
cultivation. It becomes lighter and warmer as it is stirred and is 
gradually becoming fitted for crops that at first did not flourish 
upon it. It ranks among the very best of soil. It prevails in those 
portions of Racine, Milwaukee, Waukesha, Ozaukee, Washington, 
Sheboygan, Manitowoc and Calumet counties that are heavily tim¬ 
bered, and that are not occupied by the following classes, chiefly 
the red clay. The map gives the area more definitely. 
4. THE RED MARLY CLAY SOIL. 
The term “ red clay 77 is popularly applied to a very extensive 
formation in the northeastern portion of the state and to the soil 
derived from it. It is very properly denominated a clay, if we use 
that term in a simple physical sense. It is finely comminuted, close, 
compact, adhesive and almost impervious. It washes, cracks and 
otherwise deports itself as a clay. It, however, never posesses that ex¬ 
tensive tenacity when wet, or that obdurate hardness when dry, that 
characterizes the typical aluminous clay. It contains, moreover, 
fragments of limestone, and occasionally of other rocks, that mod¬ 
ify these qualities. Chemically, however, it is not a true clay. 
There is a very notable proportion of silica, lime and magnesia. 
The application of acid to the deeper sub-soil, almost always gives 
brisk action. It must then be regarded as highly marly in charac¬ 
ter. This large ingredient of lime and magnesia is very fortunate, 
as it adds much to the value of the soil. It also contains consider¬ 
able iron in the form of hematite and magnetite. The former gives 
the soil its deep, pinkish or purplish color. On the surface, however, 
it weathers to an ashy hue. The magnetic iron-ore is almost every¬ 
where present, as may he seen by drawing a magnet through a 
handful of pulverized soil. On the lake shore this washes out and 
forms the “ black sand 77 which may prove of some value in the 
manufacture of iron or steel. 
This soil needs thorough working, which is not so easily done as 
in the more loamy and sandy soils, but it yields excellent returns. 
It is an exceedingly strong, fertile, durable soil. Its strength lies 
