Determined to learn the secret of the old mill, Frank and Joe employ a clever use to gain entrance and become trapped. There they unravel two mysteries, one involving a counterfeiting case and the other, a national security case their father is working on.
Asimov's Mysteries, published in 1968, is a collection of 14 short stories by Isaac Asimov, all of them science fiction mysteries (although, as Asimov admits in the introduction, some are only borderline). The stories were all originally published in magazines between 1954 and 1967.
Archaeology for Kids: Uncovering the Mysteries of Our Past, 25 Activities (For Kids series) by Richard Panchyk
Twenty five projects such as making a surface survey of a site, building a screen for sifting dirt and debris at a dig, tracking soil age by color, and counting tree rings to date a find teach kids the techniques that unearthed Neanderthal caves, Tutankhamuns tomb, the city of Pompeii, and Tenochtitlan, capital of the Aztec empire. Kids will delight in fashioning a stone age tool, playing a serialization game with old photographs of cars, reading objects excavated in their own backyards, and using patent numbers to date modern artifacts as they gain an overview of human history and the science that brings it back to life.
Learn the purpose of ley lines and ancient megalithic structures located on the grid. Discover how the grid made the Philadelphia Experiment possible. Explore Coral Castle and other mysteries including acoustic levitation, Tesla shields and Scalar wave weaponry.