page_title: Bonshō
section_title: Construction
hierarchical_section_title: Bonshō / Construction
caption_attribution_description: English: Diagram showing the various parts of a Japanese temple bell.
context_page_description: Bonshō, also known as tsurigane or ōgane are large bells found in Buddhist temples throughout Japan, used to summon the monks to prayer and to demarcate periods of time. Rather than containing a clapper, bonshō are struck from the outside, using either a handheld mallet or a beam suspended on ropes.
  The bells are usually made from bronze, using a form of expendable mould casting. They are typically augmented and ornamented with a variety of bosses, raised bands and inscriptions. The earliest of these bells in Japan date to around 600 CE, although the general design is of much earlier Chinese origin and shares some of the features seen in ancient Chinese bells. The bells' penetrating and pervasive tone carries over considerable distances, which led to their use as signals, timekeepers and alarms. In addition, the sound of the bell is thought to have supernatural properties; it is believed, for example, that it can be heard in the underworld. The spiritual significance of bonshō means that they play an important role in Buddhist ceremonies, particularly the New Year and Bon festivals.
context_section_description: Bonshō are cast in a single piece using two moulds, a core and a shell, in a process that is largely unchanged since the Nara period (710–794). The core is constructed from a dome of stacked bricks made from hardened sand, whilst the shell is made using a strickle board. This is a large, flat, wooden board shaped like a cross-section of the bell, which is rotated around a vertical axis to shape the clay used for the mould. Inscriptions and decorations are then carved or impressed into the clay. The shell fits over the core to create a narrow gap, into which the molten bronze is poured at a temperature of over 1,050 °C (1,920 °F). The ratio of the alloy is usually around 17:3 copper to tin; the exact admixture (as well as the speed of the cooling process) can alter the tone of the end product. After the metal has cooled and solidified, the mould is removed by breaking it, therefore a new one has to be created for each bell. The process has a high failure rate; only around 50 per cent of castings are successful on the first attempt, without cracks or imperfections.
  The casting is traditionally accompanied by the chanting of Buddhist sutras, which may go on for several hours. Buddhist prayer papers, sprigs of sacred mulberry and other ceremonial offerings are added to the molten bronze during the founding process.
  There are several parts to a temple bell:
  Ryūzu (竜頭), the dragon-shaped handle at the top of the bell, by which it is carried or hung
  Kasagata (笠形), the domed crown of the bell
  Chi or nyū (乳), bosses around the upper part of the bell that improve its resonance
  Koma no tsume (駒の爪), lower rim
  Tsuki-za (撞座), striking panel, a reinforced spot where the bell is struck. It is often decorated with a Buddhist lotus motif.
  Tatsuki (竜貴), decorative horizontal bands
  Mei-bun (銘文), inscription (often giving the bell's history)
  Shu-moku (手木), the hanging wooden beam used to strike the tsuki-za
  Some bells retain linear impressions arising from joints in the mould used; they are not removed during fettling but are regarded as an aspect of the bell's overall beauty. The bell's appearance and sound are intended to be in keeping with Japan's wabi-sabi aesthetic.
caption: Diagram showing the various parts of a Japanese temple bell
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