Much has been recently published relating to the performance and failu
re mechanisms of church and cloister bells, However, there has been no
attempt to correlate such data with the microstructure, chemical comp
osition, design and sound of bells, Thus, some of the published hypoth
eses and assumptions have been made with minimal scientific basis. in
this article various features relating to the bell-making process in d
ifferent centuries are discussed, including information based on metal
lographic and chemical analyses of bell material taken from a number o
f bells cast between 1556 and 1995, We also consider the implied exten
t of the scientific knowledge of bell-makers from the Middle Ages and
investigate the validity of some of their generally held theories for
the creation of sound, defect-free artefacts, while recognizing their
enormous practical skills.