El ferrocarril transcontinental (The Transcontinental Railroad)

People today refer to the Midwestern and prairie states as flyover country. During the Civil War, crossing those areas was the biggest obstacle in uniting the East and West Coasts of our divided nation. An act of Congress in 1862 authorized the Central Pacific and the Union Pacific railroad companies to build a railroad that would link the coasts. Seven years later, on May 10, 1869, an overwhelmingly immigrant labor force completed the task when a rail line was join in Promontory, Utah. The states had become united at last.

Juancho wanted a dog so badly that he draws one. Since it is his own creation, it is the perfect dog for him and they get along very well. Sadly, one day the dog vanishes. But Grandma saves the day?

It doesn't take a lot to conserve electricity. Taking action can be as simple as turning off the lights when you leave a room or using "people power" instead of cars to get around. Kids learn this and more about what they can do to help in 10 Things I Can Do to Save Electricity. Now in Spanish.

Many children have heard of dams, but not many know what they are. This book engages young readers as it reveals the many fascinating aspects of the worlds largest dam, which was built on the border of Paraguay and Brazil.

Quizá los trilobites no sean tan espectaculares como los grandes dinosaurios. Sin embargo, estos pequeños seres prehistóricos –los cuales vivieron durante el periodo Cámbrico, es decir hace 542 millones de años–, tienen mucho que decirnos sobre el pasado remoto de la Tierra y sobre los seres vivos en general. Su fascinante anatomía, por ejemplo, guarda curiosas similitudes con otros animales y con un sinfín de objetos de uso común hoy en día. Este ameno libro toma a los trilobites como tema para hablarnos de la biología pero también de ingeniería. Los autores se refieren lo...