Bell metal metal used is a high-tin alloy of copper and tin with approximately a 4:1 ratio of copper to tin (78% copper, 22% tin). This is a much higher tin component than that used in statuary bronze. A range of percentages of tin content can vary from 20 to 26%, depending on the founder who has arrived empirically at their own alloy ratio. It has been found that increasing the tin content increases the decay time of the bell strike, thus making the bell more sonorous. Taking into consideration overall properties, such as tensile strength, hardness, wear resistance, cast quality, sound,
Sundown Tin and Copper Mine to calcine the tin concentrates and drive of arsenic and sulphur. In 1917 a Merton calciner was erected and flues for arsenic recovery constructed. It is likely that these replaced the old reverberatory furnace and calciner. Arsenic became and important product of the mines, the demand escalating during the prickly pear infestation. New shafts were sunk at both the tin and copper mines. The lack of water reduced output in 1918, only 23 tons of tin and 12.5 tons of copper concentrates being produced, but the new shafts were continued, the three compartment copper shaft having poppet legs and ore