Conservational principles do apply, however, to the human energy factor required for their efficient use.
The importance of this fact from the conservational standpoint cannot be too much emphasized.
Another considerable group of conservational practices is possible only to governments or other public agencies.
Illustrations of these two types of conservational effort are cited in relation to coal on later pages.
It becomes an asset––a conservational asset––an ever-present help in time of haying.
There are certain difficulties, however, in the way of this conservational measure.