It is believed that the development of our knowledge during the last few years fully justifies this course. The theory of ionization has also been freely used, as the only means we have by which a large class of phenomena can be clearly presented and understood. It seems desirable to give some material which it is not possible to emphasize or teach thoroughly in a brief course and some things which are rather for reference than to be learned. To aid teachers and students in distinguishing such paragraphs, they are indicated by an asterisk. 

MOST adolescent boys and girls are more interested in themselves than in abstract problems. Although colleges emphasize mathematics and languages in their entrance requirements and say little about science, there has been a rapid growth in the number of sciences elected in the high schools.
This is primarily due to the realization that science is more a part of the lives of pupils than other school subjects and an answer to more of their questions.

The ultimate destinies of our race — concerning also the nature of other worlds and states of existence differing from those of our present life — checked and examined at every pointy verified in all directions and constantly under examination throughout has come to be looked on by its custodians as constituting the absolute truth concerning spiritual things, the actual state of the facts regarding vast regions of vital activity lying beyond this earthly existence.

(Electricity and Magnetism)

Before electricity generation began slightly over 100 years ago, houses were lit with kerosene lamps, food was cooled in iceboxes, and rooms were warmed by wood-burning or coal-burning stoves. Beginning with Benjamin Franklin's experiment with a kite one stormy night in Philadelphia,the principles of electricity gradually became understood. In the mid-1800s everyone's life changed the electricity.

AMONG the ranks of the great astronomers it would be difficult to find one whose life presents more interesting features and remarkable vicissitudes than does that of Galileo. We may consider him as the patient investigator and brilliant discoverer. We may consider him in his private relations, especially to his daughter, Sister Maria Celeste, a woman of very remarkable character ; and we have also the pathetic drama at the close of Galileo's life, when the philosopher drew down upon himself the thunders of the Inquisition.