Darci Nash, age 7, of Eugene, Ore., for her question:

HOW DOES A MAGNIFYING GLASS WORK?

A magnifying glass is a lens that makes tiny objects appear larger. It's just the tool you'll need if you are looking at a long list of names printed in agate type.

Both sides of a magnifying glass' lens are usually curved to form a double convex lens. Held close to the page in a book, the image formed is called a virtual image. The light rays which produce this image spread out as they pass through the lens and appear to originate on the same side of the lens as the page. The virtual image appears upright and larger than the object.

A real image is formed when light rays from an object pass through the lens and are focused on the other side. The image appears inverted, and its size depends on the distance of the object from the lens.