Inō Tadataka

Hello! My name is Inō Tadataka. For many years, I lived in a town called Sawara in Japan and ran a family business. But I always had a secret dream: I wanted to learn all about the stars and the size of the Earth. When I turned 49 years old in 1794, I decided it was finally time to follow that dream.

Even though I was a grown-up, I wanted to learn more! So, in 1795, I moved to the big city of Edo, which is now called Tokyo. I became a student of a famous astronomer named Takahashi Yoshitoki. He taught me how to use special tools to measure the land and study the stars. My biggest goal was to find out just how big Japan really was.

In the year 1800, when I was 55 years old, I started the biggest adventure of my life. The leader of Japan, the shogun, gave me permission to travel and measure the entire country. For the next 17 years, my team and I walked all over Japan. We walked along windy coasts, over tall mountains, and through quiet villages. We used our tools to measure every step and carefully drew what we saw.

After all those years of walking, we had enough information to make a beautiful, accurate map. I worked on it until the very end of my life. I lived to be 73 years old, and my students finished the final map in 1821. It was the very first complete map of Japan made from real measurements! People used my maps for over 100 years to travel and learn about our country. I hope my story reminds you that it's never too late to learn something new or go on a great adventure.