Evening star., 1948-12-10
Earth Has Four Skins,
Navy Scientists Find
Varying Thicknesses Indicated; Alsas
Studied as Food Source
Stars, Men and Atoms
By Thomas r. Henry

By Thomas r. Henry
The earth has four skins
Experiments with high explosives made
available by the Navy to physicists OF the
Carnegie Institution Of Washington after the
war reveal the existence of these four layers
of rock, according to the report of the In.
stitution's Department Of Terrestrial Magnet
ism. A powerful explosion set of on the sur.
face creates artificial earthquake waves, some
of which can be picked up as much as so miles
away. Their paths can be calculated
The results for the central Appalachian re-
gion show that these waves travel at four diff
ferent rates. depending on the depth to which
they have penetrated. First is region extend
ing to depth of about miles Immediately
below the surface, where the waves move at o
speed of about four miles q second. Then
comes a layer approximately eight miles thick
through which movement Is at q slightly
greater speed The next layer, characterized
by still faster movement, is about II miles
thick. Below approximately rs miles the
speed remains constant at any depth which
can be reached.
Increasing Density Seen.
These increasing speeds with depth are pre-
sumed to indicate rock layers of increasing
density. All four, however, may be considered
as parts of the earth's crust, wrapped around
a far denser region which itself surrounds the
central core of the planet
Similar experiments are being carried out
at the New Mexico School Of Mines at Al.
buquerque. While they have not progressed a.
far as those in the vicinity Of Washington,
they have confirmed the existence Of q super.
ficial layer, about eight miles thick, below
which the man-made earthquake waves move
at different speed
Foundations of new agriculture raising OF
green algae for fat-are being laid by Carnegie
Institution biologists.
They have found, according to q report to
the institutions trustees by DR.. II. A. spoehr
and his associates of the Division Of Plant
Biology, that one species of algae can be made
to produce as much as IS per cent of Its dry
weight In edible fat when grown under certain
conditions.
Proteins Also Produced.
When these conditions are changed slightly,
1t produces mainly proteins, the nitrogen-con.
tanning molecules which are the building
stones of the body. Ordinarily the algae are
chiefly made up of starches and sugars. Three
primary substances are necessary in human
and animal food-carbohydrates fats and pro.
teins. The former constitute the fuel of the
body furnace They are relatively cheap.
abundant and easy to grow Fats and pro-
teins tend to be scarce and expensive and are
obtained chiefly from animal products
The fat production by the algae is phe.
nomenal compared to that of any other farm
crops The best production obtained was
1880 pounds an acre in 120 days. The closest
approach to this was with fax seed-51a
pounds an acre in the same period. Peanuts
ran third-360 pounds an acre.
The algae to which this particular type be.
longs are one-celed plants and among the
most primitive and hardest forms Of life on
earth.
The production facts have been well estab-
nshed DR.. Spoehr says, but economical meth.
ods of cultivation and the techniques of exc
traction remain to be determined. great
advantage he stresses, is that this crop could bs
grown over and over again through the year.
whereas nearly every other crop plant is con.
fined to definite growing season
The fats, it appears, would be Immediately
available for food. 1t is not yet clear whether
the proteins would be suitable for animal con.
sumption.