Banshu abacus Banshu soroban
Upholding the spirit of “read, write, do math by abacus”
Diamond-shaped chamfered abacus of exquisite beauty
What is Banshu abacus ?
Banshu Soroban refers to abacuses produced in Ono City located in the center of Higashi Harima that is in the southeast of Hyogo Prefecture. Blessed with warm weather, Ono City engaged in abacus production during off-peak times of farming.
Banshu Soroban is characterized by its production process divided into several phases by part, and it became synonymous with Hyogo’s tradition craft by virtue of high productivity and prodigious techniques.
Otsu Soroban introduced from Nagasaki is believed to be the origin of the current Banshu Soroban. As a transportation hub bustling with Oumi merchants, Otsu was conveniently situated with easy access to the commercial capitals such as Osaka and Kyoto and noted for abacus production.
Banshu Soroban for everyday use at schools or shops went into volume production while developing user-friendly abacuses with colors and shapes that could draw children’s interests.
Though the recent proliferation of computers and calculators has brought about flagging demand for abacuses, Banshu Soroban remains a vital item in education at home and school.
History of the abacus harks back to the late Muromachi Period, when abacuses were introduced from China to Otsu City of Shiga Prefecture through Nagasaki Prefecture. Otsu’s convenient location to business districts, Osaka and Kyoto, prodded the abacus production, which contributed to the development of Otsu Soroban.
In 1580, Toyotomi Hideyoshi laid siege to Miki Castle in Miki City, forcing residents to escape to its neighboring city, Otsu. The residents who had acquired the techniques of making abacuses began the abacus production after they returned home in Otsu, which is deemed as the beginning of Banshu Soroban.
During the Edo Period, education was conducted widely in Terakoya (private elementary schools in Edo period) to encourage children to start learning “reading, writing and doing math by abacus.” Abacuses soared in popularity especially in business districts in keeping with the explosive spread of Terakoya, resulting in 8 abacus wholesalers and over 200 subcontractors by the end of Edo Period.
Following the Sino-Japanese War, in Ono City a newly-developed Ogawa type bead making machine was phased in, enabling mass production. Abacuses continued growing in demand with the economic growth once the School Education Law was implemented after the World War II.
Abacuses have experienced a slowdown in demand due to the widespread use of computers but still boasts full production with output of 530,000 a year.
General Production Process
- 1. Making a frame
This process is of making a frame out of ebony wood imported from Africa or Indonesia, or accumulate timber. It involves breaking wood into a large piece, cutting wood into smaller pieces, and processing a plate to dimensions of a frame.
- 2. Making beads
Banshu Soroban undergoes over 100 processes which are professionally crafted by respective expert artisans.
Tamakezuri is carried out after raw wood is selected and dried completely.
Abacus beads are mainly made of boxwood which is known as wood hard enough to break an ax, while boxwood, ebony wood and red sandalwood are used to make beads for a premium abacus.
Tamakezuri is a process of slicing raw wood into rounds, punching out a piece into rounds and shaving it into a bead shape. There is a new technique of making beads out of a long round bar.
- 3. Making rods
Abacus rods are mainly made of Japanese timber bamboo, while smoked bamboo is used to make rods for a premium abacus.
A bamboo stick is cut to a specified size and broken into smaller pieces, and the stick pieces are rounded and smoothed.
Banshu Soroban employs a divided production process system that requires abacus frames, beads and rods to be processed at respective plants.
All the processed materials are transferred to other artisans for further processes to assemble.
- 4. Frame processing
Frame processing is of making holes in the frame boards. The top and bottom frame board and right and left frame board need plane finishing, and the planed frame boards are made with grooves and holes. A plane is a tool used to flatten and impart a smooth surface. A backboard fits in grooves in the frame, and holes are aligned with rods and back rods.
A backboard is made out of a specified board, and holes are made in the beam (hari) that fits in between the top and bottom frames. With holes made for a bamboo rod to pass through, grooves are made in the beam and a celluloid string is embedded in the grooves.
Made of bamboo, the rods are tenoned (hozo) for final frame assembly. Temporary assembly is carried out before actual assembly to see if the frame needs a fine adjustment to assure smooth further process.
- 5. Inserting rods and beads
The rods are inserted in the holes in the beam, and the beads are threaded on the rods.
- 6. Assembly
With the beads threaded on the rods, the bottom frame, right frame, backboard and back rod are attached in sequence.
- 7. Making holes for medake-dome, urabo-dome and sumi-dome
This process is of making holes in the top and bottom frames for medake-dome, urabo-dome and sumi-dome, and cutting an inserted aluminum wire with scissors to secure the back rod, rods and right and left frames properly, giving the abacus durability.
- 8. Polishing
Polishing is a process of giving a polished finish to a part of the frame where a hand grips and filing the end of a cut wire. With sandpaper or muku tree (Aphananthe aspera) leaves, polishing finish imparts luster to Banshu Soroban.
Where to Buy & More Information
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