Before embarking on their famous transcontinental crossing Meriwether Lewis and William Clark had many questions: how long would their journey take? What obstacles would they face? And most importantly what tools would they need to survive?   In this fascinating account of Lewis and Clark's early-nineteenth-century scientific expedition learn about the monumental engineering feats they used to make their trip a success. To ensure a safe passage they took state-of-the-art tools and gear including an experimental collapsible boat a prototype air gun the first chronometer and a "spontoon"-a type of European lance.   From day-to-day survival to the scientific experiments they conducted find out how planning technology craftsmanship improvisation and sheer determination were all key to the triumph of the most audacious expedition of the era.