loamy and inexhaustible. In the main, it is of a
generous quality, so pertinaciously retaining fertilizers as to
withstand the washing of the heaviest rains. Still it is an anomaly
that some of the richest areas in this region will not produce wheat;
while, in the cultivation of rye, oats, and corn, satisfactory results
are almost invariably obtained. Likewise there are but a few parcels
whereon white clover does not grow spontaneously and in the greatest
abundance. Than these, better pasture lands are found nowhere east of
the Blue Ridge. Limestone occurs here in vast quantities.

In the Valley of Loudoun, between the Catoctin and Blue Ridge
mountains, the soil is formed from gneiss, clay-slate, hornblend,
greenstone, and quartz. The happy combination of these materials
produces a most excellent and durable soil, containing, in fair
proportions, alumina, silex, potash, lime, and other fertilizing
minerals. Certain fertilizers have been successfully employed in
improving its natural fertility, and when it is partially exhausted by
excessive tillage, rest alone will restore it.

_Loudoun Sandy Loam._

The Loudoun sandy loam consists of from 8 to 12 inches of a heavy
brown or gray sandy loam, underlain by a heavy yellow or red loam or
clay loam. Often the subsoil contains a considerable quantity of
coarse sand, making the texture much the same as that of the soil. The
sand of the soil and subsoil is composed of very coarse rounded and
subangular quartz particles. The surface material is not a light sandy
loam, but is more like a loam containing considerable quantities of
very coarse quartz fragments. It is generally quite free from stones,
but small areas are occasionally covered with from 5 to 20 per cent of
angular quartz fragments several inches in diameter.

The Loudoun sandy loam occurs in irregular areas of considerable size
in the intermediate valley between the Blue Ridge, Short Hill, and
Catoctin mountains. The largest area of the type is found in the
vicinity of Round Hill.

The topography of this soil in the valley varies from gently rolling
to hilly, the slopes being long and gently undulating, while along the
valley walls and in the uplands it is ridgy. Owing to the position
which this type occupies, surface drainage is good. The light texture
of the soil admits of the easy percolation of water through it, and,
except where the subsoil contains considerable sand, the soil moisture
is well retained. I