Mechanical engineer Tim Leatherman invented Leatherman Multi-tool . 3 . Early batteries only powered the first flashlights briefly , hence the name `` flashlight '' 17th century Spanish and Portuguese sailors used ship sails to make duffle bags . The modern battery is a chemical reaction between two electrodes ( metal ) that produce electricity when they are in contact with one another.
Mechanical engineer Tim Leatherman invented Leatherman Multi-tool . Early batteries only powered the first flashlights briefly , hence the name `` flashlight '' 17th century Spanish and Portuguese sailors used ship sails to make duffle bags . The modern battery is a chemical reaction between two electrodes ( metal ) that produce electricity when they are in contact with one another.