Walker, Sally M

Explores the different ways geologists can research rocks and what that research can tell us about rocks.

Presents a history of the Mason-Dixon line, including how it came to be, and the symbolism it holds in America. Includes black-and-white illustrations.

Describes a sea horse living in the coral reefs of the central Philippines, its habitat, life cycle, food, and how it protects itself from predators.

Provides an account of the disaster that occurred on December 6, 1917, when two ships carrying munitions and relief supplies to Europe collided, causing an explosion that leveled the towns of Halifax and Dartmouth and resulted in the deaths of nearly two thousand people.

Describes soil, how it is formed, and why it is studied.

Opossum and her babies encounter danger as they search for food at night.

Presents a children's book for early readers that describes how pulleys are used and how they can make work much easier.

Describes work, machines, levers, and force in everyday surroundings, and presents experiments that explain how they work.

Explores the science of light, discussing such topics as reflection, refraction, and color and describing experiments that demonstrate their properties.

Introduces vocabulary and concepts related to electricity, exploring atoms, electrical charges, static electricity, circuits, and other topics and presenting several hands-on activities.