The Jackson-Gwilt Medal is an award that has been issued by the Royal Astronomical Society (RAS) since 1897. The original criteria were for the invention, improvement, or development of astronomical instrumentation or techniques; for achievement in observational astronomy; or for achievement in research into the history of astronomy. In 2017, the history of astronomy category was removed for subsequent awards and was transferred to a new award, the Agnes Mary Clerke Medal.The frequency of the medal has varied over time. Initially, it was irregular, with gaps of between three and five years between awards. From 1968 onwards, it was awarded regularly every three years; from 2004 every two years; and since 2008 it has been awarded every year. The award is named after Hannah Jackson née Gwilt. She was a niece of Joseph Gwilt (an architect and Fellow of the RAS) and daughter of George Gwilt (another Fellow); Hannah donated the original funds for the medal. It is the second oldest award issued by the RAS, after the Gold Medal. Source: Wikipedia (en)