1. Origins of the performing arts and stages in Japan

According to Japanese mythology, the performing arts in Japan originated in a dance performed by the goddess Ame-no-uzume in front of Ama-no-iwato, the Gate of the Celestial Rock Cave, to assuage the anger of Amaterasu, the Sun Goddess. This dance, performed on an overturned tub, became the precursor of stage performances, according to the myth. The performing arts became integral parts of festivals and then dinner celebrations early in Japan's history ⁽¹⁾. Although no audience is required for painting or other such artistic fields, the existence of an audience is crucial to the performing arts. One can argue that the performing arts arose as a natural offshoot of man' involvement with deities and a belief that a response could be elicited through performance.
Stages originally were temporary constructions, but with the introduction and popularization of Dengaku, Noh and Kabuki plays, stages become permanent structures. Because of the connection between the performing arts and religion, stages were normally constructed on the grounds of shrines or temples or somewhere nearby. Kabuki traces its roots to a "Kabuki Odori" dance performed in Kyoto in the early Edo Era (1600-1868) by the woman Izumo-no-Okuni.

2. Revolving stages of theaters and rural playhouses

Although Kabuki' popularity in urban areas grew during the Edo Era, feudal lords in outlying regions in many cases prohibited such performances. Nonetheless, Kabuki took root throughout the country as a popular form of entertainment because of performances by licensed performers from the cities and others who managed to work around the prohibition. Actors at first-rate theaters in Edo (now Tokyo), Kamigata (now Osaka) and Kyo (now Kyoto) were professionals, but actors in rural productions generally were amateurs or local performers. According to a study conducted in 1970, there were some 1,800 stages in rural Japan during the Edo Era, approximately 1,000 of which still exist. Kabuki continued to flourish in the Meiji Era (1868-1912), but in modern times the number of rural theaters has declined because of the diversification of entertainment, the desire of young people to move to urban areas, and the aging of theaters.
Although the number was few, playhouses where the performers and audience were under a single roof did exist in rural areas. The first revolving stages, referred to as bun-mawashi, were developed by Denshichi Nakamura and introduced in the years 1715-1735 of the Edo Era. These were actually double stages, composed of a separate revolving stage placed on top of the normal stage. In 1758, Shozo Namiki formed a new type of revolving stage in the Kadoza area of Osaka by cutting a circular section out of the normal stage and rotating this during performances, thus enabling performances to switch from one scene to the next without the drawing of a curtain. The stage was rotated by stagehands positioned in the naraku area below the stage. This technology was based on conventional karakuri mechanisms, which were sets of wooden gears used to maneuver puppets ⁽²⁾. The audience was not able to see the stagehands working below the revolving stage.
During the Edo Era, Japan produced a large number of renowned carpenters who specialized in wooden structures based on shrine and temple architecture. These carpenters, who were connected by a nationwide fellowship, displayed great imagination and skill in their work and were able to create very unique stages based on the particular requests of people in rural communities. Generally there was no roof over the audience at rural theaters in the Edo Era, but perhaps this made it easier to create original stage mechanisms. The rural theater in Kamimiharada (in Akagi Village of Gunma Prefecture) was constructed in 1818 by master carpenter Chojiro Nagai and was designated an Important Cultural Property in 1960. This carpenter had previously invented a special type of watermill, a drawbridge, and a model of a large flying device resembling a crane, and applying this same ingenuity to stages, he created stages whose sidewalls could be laid outward to extend stage width, stage mechanisms that made it possible to view the stage' rear area from a distance, revolving stages, and mechanisms for raising stage trapdoors.
Although there are records indicating that temporary apparatuses resembling revolving stages were used in Grecian times and during the time of Louis XIII, these were very rudimentary. The first mechanism in Europe comparable to the revolving stages of Japan was the drive-type revolving stage installed in 1896 in the Bavarian Royal Theater of Munich in Germany. According to historian Kitsutaro Sugino, "The revolving stage of the Bavarian Royal Theater was constructed approximately 170 years after Denshichi had invented the bun-mawashi revolving stage, 128 years after Shozo had improved this stage, and 28 years after the beginning of Japan'sMeiji Era. By this time, Kabuki had certainly made its way to Europe, and the constructors of the Bavarian Royal Theater stage had likely observed Kabuki" ⁽³⁾. In addition, the first edition of Siebold' Nippon mentions that the Kabuki play Imoseyama-onna-teikin was performed on a revolving stage. It is an established belief that revolving stages have their roots in Japan.

3. Progression of revolving stage mechanisms in the Edo Era
Revolving stages began with double stages, in which case a movable stage was installed on top of a normal flat stage. Initially, these stages were capable only of forward-reverse and left-right linear movement, but later on rotational movement also became possible. Next came the development of the "cutout" type revolving stage, in which case a circular section of the flat stage was cut out and made to rotate on the same plane as the flat stage. Thereafter, attention was given to improving the smoothness of rotation of cutout type revolving stages, and efforts were made to improve rotating mechanisms. Cutout type revolving stages were divided into two types based on the relationship between the stage and its supporting central shaft: "spinning-top" stages and "spinning-dish" stages.

1. Spinning-top stages: The revolving floor and shaft were connected, and the floor was rotated by means of rotating the shaft. The revolving floor and its rotating elements rested on an ukedai track located under the floor perimeter.
2. Spinning-dish stages: The revolving floor rotated on the top of a stationary central shaft, which was planted securely in the ground. Rolling elements such as balls or rollers were attached to a retainer and enabled smooth rotational movement. This construction is similar to that of a modern slewing rim bearing.

4. Investigation of the Konpira Theater' revolving stage mechanism

4.1 Konpira Theater
The Konpira Theater was originally constructed in 1835, near the end of the Edo Era, in Kotohira-cho, Kagawa Prefecture. This stage is the oldest and largest of its type still existing in Japan and the oldest of its type in the world. This building underwent major repairs on two occasions after its initial construction, and a restoration was completed in March 1976. According to records, a careful investigation of the building was performed during its disassembly, and the original techniques, methods, etc. were used in its reconstruction. In addition, only materials and parts with conspicuous damage were replaced; in all other cases, the original parts and materials were used ⁽⁴⁾.
4.2 Revolving stage structure and rotating mechanism
In regard to its structure, the revolving stage of the Konpira Theater is largely the same as other revolving stages, with its mechanism resembling those of later stages . An outline of the revolving stage mechanism is shown in Figure 1⁽⁵⁾. This revolving stage is the cutout, spinning-dish type and has a cage & roller apparatus in which rollers have been fixed to a retainer by a shaft. This cage & roller apparatus is positioned between the osaeban (upper track holding down the rolling elements) and ukedai (lower track supporting the rolling elements), which was supported by 12 pillars. The 7.19 m revolving stage was supported in its center by an octagonal pillar planted securely in the ground. The cage & roller apparatus was composed of 24 cage & roller sets, each containing three oak rollers (Figure 2).

Fig. 1 Outline of the Konpira Theater revolving stage.

The central pillar has been planted 2.1 m into the ground and rests on bedrock. The stage is rotated through the efforts of four stagehands. Working in the naraku area, these stagehands push on four "Push-poles," which are attached vertically to the large joists supporting the stage floor and located concentrically around the center pillar at 90-degree intervals, each 2.3 m from the center. There also were "Push-stones" located in the ground around the walking path at 0.24 m intervals, which enabled the stagehands to push in unison and improved rotational smoothness. The centering mechanism of the revolving stage was a center pivot. A metal protrusion located on the central pillar' top end fit into a metal fitting inserted in a hole cut in the bottom center of the main beam attached to the stage bottom ⁽⁵⁾ (Figure 3). The vertical load of the stage rested both on the pivot bearing area of the central pillar and on the cage & roller apparatus in contact with the bottom of the revolving stage' perimeter.

Fig.3 Pivot mechanism and cage & roller area sketches

5. Wooden revolving stages of the Edo Era

Theaters constructed around the same time as the Konpira Theater that are likewise equipped with revolving stages include the Kamimiharada Kabuki Theater in Akagi Village, Gunma Prefecture, and the Hitoyama Kabuki Theater on the island of Shodoshima, Kagawa Prefecture. In the case of both of these revolving stages, rollers or wheels positioned along the bottom perimeter of the revolving floor enable rotational movement. Also, in order to prevent rotational deviation, the Konpira Theater has wooden projections along the cage & roller apparatus circumferential exterior, the Kamimiharada Kabuki Theater has support wheels attached horizontally to the revolving floor circumference that fit into the fixed stage, and the Hitoyama Kabuki Theater has the same type of structure but with elliptical spheres instead of support wheels. The wisdom of such mechanisms cannot be overlooked.

6. Rotational mechanisms of the Meiji Era (1868-1912) and Taisho Era (1912-1926)

The rotational mechanisms of the Konpira Theater' revolving stage and similar stages of the Edo Era were adopted by numerous theaters in Edo, Osaka, Kyoto and other places. Most of these theaters no longer exist, but the stage systems and mechanisms thereof were passed along to theaters constructed in the Meiji Era and Taisho Era. Moreover, the Industrial Revolution in the West had fostered significant developments in areas such as steel production, railway wheel technology and rail technology, and as Japan opened up to the world in the Meiji Era, it engaged in technology transfers and exchanges, resulting in advances in the rotational mechanisms of revolving stages in Japan. Among stages of this period still existing and functional are the Kureha-za Theater in Ikeda, Osaka Prefecture (later transferred to Meiji Village in Aichi Prefecture), constructed late in the Meiji Era; the Korakukan Theater in Kosaka, Akita Prefecture, constructed in 1911; the Yachiyo-za Theater in Yamaga, Kumamoto Prefecture, constructed the same year; the Uchiko-za Theater in Ehime Prefecture, constructed in 1929; and the Kaho Theater in Izuka, Fukuoka Prefecture, constructed in 1936. The proliferation of theaters around this time was a result not only of the growing popularity of Kabuki but also of the development of cities in outlying areas and the desire for theatrical entertainment among those involved in the fast-expanding mining industry in rural areas.
During this period wheels were made of steel. In some cases these wheels were attached to the ukedai and a metal plate attached to the revolving stage underside rolled on top of them, and in other cases the wheels traveled around the perimeter on top of a steel rail. Such wheel technology is thought to reflect Western influence and the introduction of mining cartequipment. The name "Kruppe" is engraved on the rails of the Yachiyo-za and Korakukan theaters. However, rotation was still carried out by human power. The rotational mechanisms of these theaters were based on those of the Konpira Theater and others, which had good overall balance and could be driven by human power, and therefore human power was more than sufficient for the steel-wheeled mechanisms of these later stages.

7. Structure and rotational mechanism of the Kureha-za Theater'srevolving stage

7.1 History of the Kureha-za Theater
The Kureha-za Theater was constructed in 1874 in the Honmachi area of Ikeda, Osaka Prefecture, as the Ebisu-za Theater and was relocated to Nishi-Honmachi in the same city in 1892 and renamed the Kureha-za Theater. The theater was remodeled in Western fashion some time around 1910 and went through various changes after that, but in 1969 it was moved to Meiji Village in Aichi Prefecture, and reconstruction was completed two years later (Figure 4). In 1984 it was designated an Important Cultural Property,and repairs were carried out in 1998 ⁽⁷⁾.

Fig.4 View of Meiji Village Kureha-za Theater

Prior to the relocation of the Kureha-za Theater to Meiji Village, the original wooden central pillar supporting the revolving stage had been replaced with a stone pillar because the base of the wooden pillar reportedly had rotted. However, this was replaced once again with a wooden pillar when the theater was reconstructed in Meiji Village. A modern single-direction thrust ball bearing (standard type, call number 51109) was installed in the bearing rotational area of the central pillar when this theater was reconstructed ⁽⁸⁾. With a width of 30mm and diameter of 6,645mm, this revolving stage is relatively small. Pine is used for the beams and splints attached to the stage underside, and the overall structure is very simple.
A double-layer copper plate was attached to the bottom of the splints by means of bolts with square heads, which were commonly used from the beginning of the Meiji Era until around 1907. In the area where the wheels come in contact with the revolving floor in the perimeter rotational mechanism, there are 31 copper plates, each of which is 6mm in width and has been cut diagonally at both ends and attached by means of flathead screws. There are 16 wheel attached to the ukedai under the revolving floor perimeter, and the copper plate attached to the revolving floor underside rolls over these wheels.

8. Revolving stage of the Yachiyo-za Theater (designated an Important Cultural Property)

The Yachiyo-za Theater was constructed in 1910 and was reconstructed in 1923. This theater is a classic example of late Meiji Era design based on traditional Edo Era architecture. It has been well preserved and was never relocated. Furthermore, when major repairs were carried out from 1996 to 2001, parts were replaced with new ones as little as possible in order to preserve the original stage. Accordingly, the revolving stage, along with its steel wheels and rails (engraved with the name "Kruppe"), which were based on technology introduced from the West, has been well preserved (Figure 5), and the mechanisms and movement of this stage are the same as those that existed in 1923. A detailed report with observations will be presented at a later date, but at this point I wish to compare the friction coefficients of the above three stages.

FFig.5 Rotating mechanism of Yachiyo-za Theater (wheels and rail)

Based on actual measurements of the rotational resistance of the revolving stage rotational support mechanisms of the three theaters, a comparison of frictional force was carried out and observations made (Table 2).

Fig. 6 Mechanism of National Theater revolving stage

A history of revolving stages from the Edo Era through modern times was outlined, including actual measurement data and mechanism evaluations. Japanese original technology and skills along with technology transferred to Japan as a result of interchanges with the West were explained, and it was verified that such blending of technologies had a synergistic effect.

References

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