Muddy water is put through a process called clarification. It is the
same, except that there are no holes in the vessel. The heavier
particles of dirt, that would settle in time, take the outside, leaving
perfectly clean water in the middle. A perpendicular perforated pipe,
with a faucet below, drains off all the clear water and leaves all the
mud. Milk is brought in from the milking and put into a separator;
whirl it, and the heavier milk takes the outside of the whirling mass,
and the lighter cream can be drawn off from the middle. It is far more
perfectly separated than by any skimming.

A rotary snowplow slices off two feet of a ten-foot drift at each
revolution, and by centrifugal force flings it out of the cutting with
a speed that a hundred navvies or dagos cannot equal.




ONE PLANT HELP

A thousand acres of land on Cape Cod were once blown away. This wind
excavation was ten feet deep. It was not an extraordinary wind, but
extraordinary land. It was made of rock ground up into fine sand by
the waves on the shore.

In all the deserts of the world the wind blows the itinerant sand on
its far journeys. If the wind is moderate it heaps the sand up into
little hills, some of them six hundred feet high, around any
obstruction, and then blows the sand up the slanting face of the hill
and over the top, where it falls out of the wind on the leeward side.
In this way the hill is always traveling. In North Carolina hills