On Time - Tapa dura

A fascinating tour of time measurement through the ages. Children discover how humans learned to recognize time and began to measure it in smaller and smaller units from the precisely placed boulders at Stonehenge, which marked the equinoxes; to Egyptian obelisks, which measured the hours; to modern-day atomic clocks, which subdivide seconds.

Gloria Skurzynski has written more than 30 children s books. Her nonfiction book, Almost the Real Thing, won the American Institute of Physics Science Writing Award. She has written several nonfiction books for National Geographic including Are We Alone, an NSTA Outstanding Science Trade Book for Young People and an IRA/CBC Young Adults Choice for 2006. She lives in Boise, ID. Visit Gloria Skurzynski at her Web site: www.gloriabooks.com."