"What do jar tops and water-bottle lids have in common? Both of them are screws! Screws are simple machines. They help us to do jobs more easily. But don't take our word for it. Put screws to the test with the fun experiments you'll find in this book" -- Back cover. Provides experiments to introduce screws as simple machines, including how they function and how they are used in everyday objects to make life easier.

"From the 1870s to the 1960s, circuses crisscrossed the nation providing entertainment. A unique workforce of human and animal laborers from around the world put on the show. They also formed the backbone of a tented entertainment industry that raised new questions about what constituted work and who counted as a worker. Andrea Ringer examines the industry-wide circus world--the collection of shows that traveled by rail, wagon, steamboat, and car--and...