25 years ago: Ten people were arrested after heroin and cannabis were recovered from a chemist’s and a number of private houses in Bradford and Shipley when plain clothes police and pharmaceutical experts joined forces in a swoop.

50 years ago: Bradford-born scientist Sir Edward Victor Appleton, who discovered the Appleton Layer, an ionised region in the upper atmosphere which made short-wave radio transmission possible, and laid the foundation for radar, died suddenly at his Edinburgh home aged 72.