The person who taught me: Makio Yagi
Traveling approximately 40,000 km, the equivalent of one trip around the Earth
Ino Tadataka acquired astronomy and surveying techniques after turning 50 and handing over the family business to his son. Having had an interest in astronomy from a young age, after retiring he moved to Fukagawa in Edo and studied under Takahashi Yoshitoki, an astronomer for the shogunate.
Today, this might be considered a second life, or something to enjoy in old age. However, perhaps due to his innate earnestness, Tadataka's skills improved to the amazement of even his master, and five years later he was recommended by the shogunate to survey Ezo, setting off on his first surveying journey. Little did Tadataka himself know that this would be a long, long journey of 40,000 km, the equivalent of traveling around the globe.
The most notable feature of Tadataka's surveying journey is that he faithfully traced the coastline. This is only natural, as the purpose of the journey was to create a map of Japan based on actual measurements, but there are not necessarily roads along the coastline. The journey must have been extremely difficult.
And when, during his surveying journeys, he came across a difficult spot that he just couldn't survey, Tadataka not only recorded it on the map without any glossing over, but he is said to have even requested that the survey be carried out again. The idea that "two steps make one ken, or 40 million steps," with one step being 90 cm, is likely an exaggeration due to the legend, but there was absolutely no compromise or embellishment in Tadataka's work.
A total of 10 surveying trips over 17 years from the age of 55
Shogunate officials, who appreciated Tadataka's map of Ezo, ordered him to carry out further surveys. At the time, the Shogunate felt a sense of crisis about the appearance of foreign ships in nearby waters, and there was no doubt an urgent need for an accurate map of Japan. It is likely that Tadataka also harbored ambitions of creating a map of the entire country around this time.
The surveying teams had traversed eastern Japan up to the fourth mission, but up until then Tadataka's status was not guaranteed and most of the funding had come from his own pocket. However, a map of the eastern coastline of Japan that they had presented caught the eye of the then shogun, Tokugawa Ienari, and from the fifth mission onwards, the survey of western Japan was elevated to an official shogunate project, the staff was increased, and Tadataka was appointed a shogunate retainer.
However, even Tadataka grew old and fell ill during his travels, so not everything went well. As a result, it took him about nine years to complete all four surveying trips to western Japan.
The 17-year surveying journey came to an end with the ninth survey of the Izu Islands and the tenth survey of the city of Edo, but Tadataka was largely absent from the last two. Tadataka passed away at the age of 73, leaving the "Complete Map of the Coastal Lands of Greater Japan" unfinished. However, his disciples continued the work on the map, and it was successfully completed three years after Tadataka's death.
Another great achievement of Tadataka
When Tadataka and his mentor, Takahashi Itoki, first submitted a proposal to the shogunate to survey Ezo, they had another goal in mind: to determine the length of one degree of meridian (latitude) through actual measurement. Knowing the length of one degree of meridian would determine the size of the Earth. At the time, the meridian problem was an urgent issue for astronomers.
To measure latitude, it was necessary to walk long distances north and south while conducting astronomical observations. Although the shogunate instructed him to travel to Ezo by boat, it is said that this was why he insisted on traveling along the Oshu Kaido. In other words, Tadataka walked an average of about 40 km a day while surveying during the day, and then devoted himself to astronomical observations after dark.
When he had completed his survey of eastern Japan, Tadataka calculated that the length of one degree of meridian was 28 ri 2 bu, a figure that proved to be accurate as it is roughly the same as the length of one degree of latitude today.
A quadrant is an astronomical observation device primarily used to measure the length of one degree of the meridian. As shown in the diagram above, the angle of a particular star was observed when it was at its highest point, and the length of one degree of the meridian was measured from the difference in that angle.
Photo courtesy of Ino Tadataka Memorial Museum
Wankarashin: Invented by Tadataka. A surveying tool with a magnetic compass attached to the end of a walking stick. The fulcrum on the magnetic surface is movable, so it can always remain level even if the ground is tilted. Tadataka invented many other surveying tools, but this was the one he used the most.
Photo courtesy of Ino Tadataka Memorial Museum
Let's go to "Ino Walk"
The origins of the "Ino Walk" lie in the Millennium Walk event, which commemorated 200 years since Tadataka began his surveying. It was a walking journey around Japan that set off from Fukagawa on January 25, 1999, and finished at Hibiya Park on January 1, 2001. It covered 11,030 km over 574 days, with a total of 170,000 participants. The fact that 170,000 people were determined to welcome the millennium by steadily walking makes it hard not to feel the sustainable spirit that has remained unchanged since Tadataka's time.
Since then, the Ino Walk has become the standard. It doesn't have to be a trip around Japan. It's a walking trip that follows the path walked by the surveying team and visits places associated with Tadataka. Let's go on an Ino Walk.
[Places of connection] Discovery Ino Japan ①-⑤
The fact that he spent 17 years surveying and walking all over Japan means that there are places associated with Tadataka all over the country. Even if you just visit nearby places associated with him on the weekend, you should be able to enjoy a great one-day Ino walk.
Once you get used to walking trips, it might be a good idea to follow in the footsteps of Tadataka, who left behind some of the footsteps he walked during the Millennium Events. For example, the southern coast of Hokkaido, which Tadataka walked during his first Ezo survey, and the Sanriku coast, which he walked during his second survey, are almost entirely preserved.
The easternmost survey site (Bekka Town)
This was the easternmost point that Tadataka visited. Mamiya Rinzo took over the surveying north of this point.
Photo courtesy of Betsukai Town Board of Education
Hokkaido survey starting point (Fukushima Town)
The place where the surveying team first surveyed Ezo is now a memorial park.
Photo courtesy of Fukushima Town Tourism Association
Constellation Stone (Touni Town)
This is the only monument erected during the Edo period by astronomer Kasai Masahito.
Photo courtesy of Kamaishi City Board of Education
Former residence of Ino Tadataka (Katori City)
His former residence, located across from the Tadataka Memorial Hall, is also open to the public.
Photo courtesy of Ino Tadataka Memorial Museum
Choshi Survey Monument (Choshi City)
Mount Fuji was used as the basis for the survey. Choshi is the easternmost point from which Mount Fuji can be seen.
Photo courtesy of Choshi City Hall
[Scenic spots] Tadataka's favorite scenery ⑥-⑩
In the Survey Journal left behind by Tadataka, the phrase "What a magnificent view" appears from time to time. During the Edo period, when information about remote areas was scarce, there must have been landscapes that stopped people in their tracks, making them forget about surveying.
Tadataka left behind these landscapes as "Maps of Famous Places," separate from the "Complete Map of the Great Japanese Coast." For example, Lake Biwa and Itsukushima are still familiar tourist destinations, but if you look at them while imagining Tadataka's surprise, you'll experience a different kind of emotion. It's hard to give up on such an Ino walk.
Kujuku Islands (Kizakata Town)
When Tadataka visited, the group of small islands floating in the lagoon offered a spectacular sight.
Photo courtesy of Ino Tadataka Memorial Museum
Forty-eight rice fields (Chikuma City)
Obasute is a scenic spot that we visited on the way back from our 8th Kyushu surveying trip.
Photo courtesy of Shinshu Chikuma Tourism Bureau
Lake Biwa (Shiga Prefecture/Map of Scenic Spots)
Lake Biwa was surveyed twice on the round trip during the fifth surveying trip.
Photo courtesy of Ino Tadataka Memorial Museum
Itsukushima (Miyajimacho/Scenic Spot Map)
During the fifth mission, which was for the shogunate, the islands of the Seto Inland Sea were also carefully surveyed.
Photo courtesy of Ino Tadataka Memorial Museum
Bandokorobana (Minamikyushu City)
A view of Mt. Kaimon, which Tadataka described as "the most magnificent view in the world."
Photo courtesy of Minamikyushu City Commerce, Industry and Tourism Division
Ask the experts: Recommendations for walking trips
We can assume that Tadataka traveled with the most advanced equipment of the time. Because he had to carry heavy surveying equipment, he would have thoroughly lightened his own equipment and made his straw sandals and other footwear easy to walk in. Tadataka was undoubtedly a "master traveler" of the Edo period.
Conversely, we modern walkers also choose cutting-edge materials such as Gore-Tex for our travel gear, and we are extremely particular about the best shoes. The basic principles of walking have not changed since Tadataka's time.
If I were to try the Ino Walk, I would like to walk through the area of Ezo where the first survey was conducted. When I imagine what Tadataka must have felt as he set out for Ezo, which was virtually unexplored territory at the time, I feel an indescribable sense of romance. I would like to follow in Tadataka's footsteps exactly, starting from his visit to Tomioka Hachimangu Shrine.
However, since modern people typically walk significantly less than people in the Edo period, I wouldn't recommend suddenly going on a 40km walk in one day. It would damage your knees and other parts of your body. Start your trip with a 10km walk in one day.
By continuing to take short Ino walks, visiting nearby places associated with Tadataka, you will find that you can walk longer distances in a day and that the fatigue and pain you feel the next day will be reduced.
When I walk along the Gokaido, I think of the road as a field and walk briskly at a pace of about 6km per hour. This is my way of approaching a walking trip. I hope you all will find a travel style that suits you. (Interview)
