Map of Japan is the first map of Ino in Japan created by Tadataka Ino when there were no maps [Road to Taiga]


Do you know the person named Tadataka Ino who made the first map of Japan?

I will answer these questions.

Map of Japan is the first map of Ino in Japan created by Tadataka Ino when there were no maps [Road to Taiga]


Tadataka Ino, who created the map of Japan!



Tadataka Ino is featured prominently in social studies textbooks for sixth graders as the person who created the map of Japan.


In this article, we will introduce Tadataka Ino, who made the first map of Japan in the Edo period.

■ Summary of this article

・Ino Tadataka lives two lives

・ Tadataka Ino Unexplored feat

・The miraculous “Ino map”



Tadataka Ino Living two lives

古い日本地図 レトロ風地図

It is already 270 years ago… In 1745, in the Edo period, Tadataka Ino was born in Koseki Village, Yamabe District, Kazusa Province, in the middle of what is now Kujukurihama, Chiba Prefecture.

His childhood name was Sanjiro, and his birthplace, Koseki, was a village headman who owned a net for the sardine business, and was a wealthy family.

However, his mother, who was the daughter of the family, died when Tadataka was 7 years old, and the Koseki family was taken over by his mother’s younger brother, and the adoptive father returned to the Jinbo family with the child.

His father’s parents’ home, the Jimbo family, was also an old family head of the family, and Tadataka grew up in a privileged environment where he could devote himself to reading, writing, and learning the abacus.

In 1762, when Tadataka turned 18, he was adopted by Michi, the daughter of the Ino family, a prominent family in Sawara Village, Katori County, Shimousa Province (now Sawara City, Chiba Prefecture).

Around this time, the Ino family was not blessed with a family head, and the family’s fortunes were on the decline.


Ino Tadataka starts his second life at the age of 50

Tadataka retired at the age of 50, and in the following year (1795), he traveled to Edo to study and became a disciple of Sakuzaemon Takahashi, who was said to be the best mathematician in Japan, at the Tokugawa Shogunate’s Tenmonkata.

Tadataka was actually interested in Wasan from a young age, and decided to spend the rest of his life studying what is now called astronomy and mathematics.

He worked hard to learn astronomy, scientific geodetic methods linked to it, and advanced mathematics such as “planar trigonometry” and “spherical trigonometry” as its foundation.

He measured the height of the sun at noon, observed the stars in the evening, and persevered in making cumbersome calculations that the average person would never have been able to do.

He called the calculation of the positions of celestial bodies “progress” at the time.

Around this time, Tadataka heard a rumor about Russia’s invasion of Ezo (present-day Hokkaido). The shogunate at that time, which did not even have a satisfactory map, hurriedly requested the creation of a precise map of the whole of Japan, but many declined due to the difficulty of creating it and the harsh labor work. However, Tadataka, who is over 50 years old, will undertake this difficult task.

Tadataka invents a surveying vehicle called the “Surveying Vehicle” in order to make the most of his time.

The idea was to measure the distance by rotating the wheel, but it lacks accuracy on uneven ground and slopes. Tadataka made his feet learn to take into account the pedometer, even if it is a slope, and convert it into a plane distance.

In addition, he realized that the magnet, which is the life of surveying, was not pointing correctly to the true north of the earth, and came up with a method of observing the North Star.

In addition, Tadataka spent a year practicing slope surveying in Shiba and Maruyama. As he walked around Edo, he trained in pacing.

In the 12th year of the Kansei era, Tadataka, who turned 56, finally set out for Ezo (now Hokkaido).

●Meeting method

This monotonous work is simply repeated while connecting the azimuth lines where multiple points coincide with the survey. He took 150,000 to 160,000 surveys over and over again to make one map of the area.


Tadataka Ino Unexplored feat

Tadataka’s series of work was extremely exhausting both physically and mentally. Moreover, the difficulties were not limited to practical matters. These preparation funds and work expenses are out of pocket. The allowance from the shogunate was almost non-existent.

Due to the inconvenience of transportation, we asked the shogunate to carry surveying equipment, but it was not accepted, and we were told to measure Honshu as well.

Tadataka was fed up with surveying and tried to stop surveying, but his master Takahashi Sakuzaemon Shitoki

“What you’re doing is a major undertaking that will affect the rise and fall of world calendar studies. If you stop doing it, there will be no regrets!”

Because I wrote a letter with the meaning, I was encouraged hard.

Thus, the coastal chart of the eastern half of Japan, including the eastern coast of Honshu, Tohoku, and Hokuriku, was completed five years after the survey began.


“Ino Map” like a miracle of Tadataka Ino


Tadataka’s survey continued until he was 72 years old. During this time, he walked 43,000 kilometers. It was a distance of more than one lap around the earth.

By the time he created a map of western Japan, his great achievements had come to be recognized by the people, support for Tadataka’s survey team had increased, and a system was in place for the cooperation of various domains.

On April 13, 1818, Mochi’s asthma worsened and he died at the age of 74. Three years later, Tadataka’s surveys, the “Dai Nihon Enkai Kochi Zenzu” = “Ino Map,” were handed over to the shogunate by his disciples, but the Tokugawa shogunate did not disclose this map and has kept it a secret. did.

In 1861, when a British survey ship was about to carry out surveys along the coast of Japan, the shogunate had no choice but to compromise by sending members of the shogunate to a British ship. It was “Ino Kozu” that I was given.

Captain Ward, captain of the British survey ship,

“Even if we survey, we can’t do anything better. Why is there such a wonderful map in Japan!”

They exclaimed their excitement at the results of their survey and the maps that were completely accurate.

After all, “Ino Kozu” was drawn according to the Sanson-Flamchid projection (a type of map projection method = correct area ratio) developed in Europe.

It is said that the British ships stopped surveying and only surveyed the nearby waters, and they obtained a copy of the “Inou map” and brought it back.

Based on this story, the shogunate exhibited this map at the Paris World Exposition in 1867 as the “Imperial Map,” and after the beginning of the Meiji period, based on the “Ino Small Map,” I made a map of Japan.

If Japan didn’t have “Ino-zu”, Japan’s modernization would have been greatly delayed.


I would be happy if you could refer to it even a little.

Thank you for reading to the end.


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