The Librarian Who Measured the Earth

Aside from the fact that even by the end of the book I couldn't consistently pronounce "Eratosthenes" correctly, my kids and I loved this one. Simple, thorough explanation of how Eratosthenes measured the circumference of Earth, and I love how it promotes following one's interests and continuing to research and ask questions even when the answers aren't readily available. I had no idea so much went on at the museum at Alexandria.

Somewhat over inspirational biography of Eratosthenes. There are really nice illustrations of Eratosthenes technique for estimating the circumference of the earth, however. Also a new word, "betamist". A betamist is an especially trained walker, whose paces can be used to calculate distances. Alexander of Macedon kept a few, so he could map out the empire he conquered with reasonable accuracy.

I have been looking for a copy of this book to purchase for many years. I first read it when I found it at the local library in Michigan when my older children were small. About five years ago, I remembered it, but couldn’t find it anywhere until one day I noticed it on a friend’s bookshelf. Now, I’m delighted to have my own copy! I read it to my youngest last evening, and she really enjoyed it. This is a wonderful way to talk about geometry, geography, and history—all wrapped up in a delightful story with great illustrations.

This amazing nonfiction children’s book tells the brief life story of librarian Eratosthenes and his discovery on the Earth’s circumference. Taken place in ancient Greek history, Eratosthenes is described to be a mind full of curiosity and wonder towards Earth as he makes further discoveries correlated from science and math. This book is such a wonderful and creative book that can be used with young readers to introduce introductory topics among math and science content areas. In math, this book can be used within an introductory lesson of circumference as this book goes into depth creatively about what circumference truly is. This book can also be used among science content lessons to go over the scientific method and the show more importance of formulating questions that can be tested using a scientifical experiment the way Eratosthenes tested his hypothesis on the circumference of the Earth. Additionally, author Kathryn Lasky provides fun facts throughout the book that can keep the reader engaged and amazed. I also like how this book correlated towards ancient Greek and Egyptian culture as it can be a great world history read when covering ancient history. show less

Great book! Cool illustrations and a well-told story of Eratosthenes, who since he was very little loved to ask questions and wonder about things. Great mathematical concepts woven in in the later third of the book - angles, circumference, geometry in general - but doesn't feel overly "teachy" at all - it's just a great story. In fact, it was so good that my kids were slightly disbelieving that it was true. ;)

Read to two kids, ages 9 and 5.

Eratosthenes was a person filled with wonder and curiosity. His biggest question was how to measure the earth. Knowing he couldn't walk around and measure, he decided that he was going to figure out how to measure the earth in one spot. This chief librarian of Alexandria's great library devised a way to calculate how big the earth is and his calculation was only 200 miles off from today's measurements. This story is an awesome look into the past with math that we still use today.

Great book for children in the 8-10 age range. Not so great for younger children. This book tells the story of the first person to write a complete geography book and how he figured out the measurements without the modern tools we have today. Great book that points out the good things about asking questions.