Speaking trumpet, early 18th century.
© Science Museum / Science & Society Picture Library
Speaking trumpets were common in science lecture courses in the mid 18th century, as the best shape for transmitting sound had recently been calculated. This speaking trumpet is asociated with Dr Stephen Demainbray (1710-1782), a famous scientist and lecturer of the 18th century. Speaking trumpets were used on ships or for overseeing a large workforce.