A work was commenced in 1786 which was expected to have proved of great advantage to Yedo. This was the cutting of a canal, and thereby joining several already existing channels, by which a through communication would have been opened up between Yedo, or the Bay of Yedo, and the Pacific Ocean on the east coast. The part of the province of Simosa between Yedo and the east coast is very low land, and it is generally believed that at one time the sea cut off the three provinces of Simosa, Kadsusa, and Awa, which then constituted a separate island; and that the detritus brought down, after a course of nearly two hundred miles, by the largest river in Japan, the Tonay, has filled up with alluvium the sea channel, leaving now only the passage for the fresh water of the river. In the course of the filling up, however, a large lake was left, the Een bang numa. About twenty miles above Yedo, the Tonay, coming down as one river from the Tonay district, divides into two. The one branch, receiving affluents from Hitatsi and the northern provinces, runs due east as the Bando taro, or “eldest son of Bando,” and enters the sea between Choshi and Itaku on the east coast. The other branch, running south, enters the sea to the east of the city of Yedo. The Okawa, or Great River, runs parallel with the Tonay, and passes through Yedo spanned by five bridges. Between the Okawa and Tonay, and running parallel to, and communicating by canals with both, is the Nakagawa or Middle River. By these cross canal communications the passage may be made from Yedo to the Pacific on the east, or to the northern provinces by running up to Seki Yedo, where the bifurcation takes place. It was proposed to deepen the lake, and cut through a passage from it into the Bay of Yedo.--The lower part of Yedo is so low that it is liable to be overflowed should the Tonay rise above its banks. To avert this danger, a large and important embankment, the Gongen do, has been made at Koori hashi. Should this give way, the whole of the lower parts of Yedo would be submerged, as happened, it is said, in 1844. The town of Sakura first started the project, and commenced a canal, but did not finish the work. The Shiogoon, seeing the advantages of the proposed cut, ordered the Daimios to cut the remainder of this canal (of about fourteen miles in length), each cutting as his share about 360 feet. The work, which was immediately commenced, was in six months half completed, when orders were given to cease working at it. In 1843 the work was recommenced by orders of government, but when it was within three thousand yards of being finished it was again stopped, and it continues in that position to this day.