- Yardstick, experiment with, to show leverage, [59]*-60.
- Yeast, action of, in bread making, [365].
- Yellow, in flames, [318].
- Yerkes Observatory, telescope of, [156]*.
- Zinc, in electric battery, [203]-206;
CONSERVATION SERIES
Conservation Reader
By HAROLD W. FAIRBANKS, Ph. D.
Lecturer, University of California; Geography Supervisor Berkeley Public Schools
A small book bringing out in a simple and interesting manner the principles of conservation of natural resources has long been wanted, or there has been little on the subject that could be placed in the hands of pupils. It is to answer this need that Fairbanks' Conservation Reader has been prepared.