Why is Yongle Bell a classic of China science and technology in the14th century?

Yongle Bell is made of copper, tin and lead alloy, with reasonable structure and exquisite technology. Beautiful shape, magnificent, lasting more than 50O, the sound is still round and loud, with strong penetration and obvious music effect. The bell can travel 40 to 50 kilometers and the reverberation lasts for 2 minutes. According to the measurement, the thinnest part of the bell waist is 94 mm, the thickest part of the bell lip is 185 mm, and the weight is 46.5 tons. The clock body is engraved with more than 227,000 words of Yang Wenkai's books and Buddhist spells. The font is neat and tough, and it is said that it was written by Shen Du, a calligrapher in Ming Dynasty. It is a classic of China science and technology in14th century.