considering its contents, which is as absurd as to estimate a man's
wealth by the size of his safe. The difference in point of view is well
illustrated by the old story of the city chap who was showing his farmer
uncle the sights of New York. When he took him to Central Park he tried
to astonish him by saying "This land is worth $500,000 an acre." The old
farmer dug his toe into the ground, kicked out a clod, broke it open,
looked at it, spit on it and squeezed it in his hand and then said,
"Don't you believe it; 'tain't worth ten dollars an acre. Mighty poor
soil I call it." Both were right.

[Illustration: Courtesy of American Cyanamid Co.

FIXING NITROGEN BY CALCIUM CARBIDE

A view of the oven room in the plant of the American Cyanamid Company.
The steel cylinders standing in the background are packed with the
carbide and then put into the ovens sunk in the floor. When these are
heated internally by electricity to 2000 degrees Fahrenheit pure
nitrogen is let in and absorbed by the carbide, making cyanamid, which
may be used as a fertilizer or for ammonia.]

[Illustration: Photo by International Film Service

A BARROW FULL OF POTASH SALTS EXTRACTED FROM SIX TONS OF GREEN KELP BY
THE GOVERNMENT CHEMISTS]

[Illustration: NATURE'S SILENT METHOD OF NITROGEN FIXATION

The nodules on the vetch roots contain colonies of bacteria which have
the power of taking the free nitrogen out of the air and putting it in