94 TEACHING SCIENCE IN SECONDARY SCHOOLS

 5. Keeping informed about new applications of science
 which appear with bewildering frequency. (New theories
 require continuing study.)
 6. Scientific meetings and activities, each of which requires
 special planning.
 Laboratory work will mean more to students if the instruc-
tor has a free period to prepare for it. In many schools an at-
tempt at load adjustment has been made to provide this period.
The principal may eliminate the home-room duties or the study-
hall assignment from the science teacher's schedule. This is not
for the teacher's convenience but in order that science students
may benefit from their work. It would be advisable for the
administrator to explain this adjustment in open faculty meet-
ing.
 Science teachers have found the following practices to aid in
the efficient expenditure of energy and time:
 1. Well considered lesson plans save energy in essential work
 when demands are heavy. The plans can be made when"
 other duties are lighter. They should be constantly re-
 vised on the basis of experiences and differences in classes.
 2. Either the pace or the topic should be varied every seven
 to ten minutes when mental concentration is desired. At-
 tention span is a psychological reality against which much
 energy may be needlessly expended.
 3. The teacher should systematize his habits-should or-
 ganize his work. The Art of Thinking by Ernest Dimnet
 discusses many time and energy savers. Energy saved in
 daily affairs will be available for forceful teaching.
 4. Train students for routine tasks such as erasing boards,
 checking roll, passing out papers, mixing solutions, filing,
 cleaning the laboratory, operating projectors and many
 other duties that can be done by young people. Commit-
 tees of students may plan details for field trips, auditorium
 programs, radio broadcasts and newspaper articles. Supe-
 rior students may learn by conducting reviews, drills,
 and make-up work for others who will also profit from the
 procedure. Competent students may monitor study halls.