When did our ancestors start using tools? How did ancient cultures deal with illnesses? How were new lands discovered? How did scientists learn about the universe and its cosmic secrets? How did people travel before engines were invented? This encyclopedia on inventions and discoveries will answer these and many more hows and whens for you. Learning is made simpler with well-labelled diagrams and an extensive glossary of difficult words. Bonus: the engrossing book comes loaded with Isn' t It Amazing— a section of fun facts to keep you glued for more.This encyclopedia is a must-read for all children!