Sepia toned photograph of 13 1/4 in. spark induction coil constructed by Russell J Reynolds and his father John Reynolds. Inscription on reverse reads: 'Coil constructed - 1896-97 Account in English Mechanic Feb 11-1898 Russell J Reynolds' , c.1898

Russell John Reynolds (1880-1964) was an internationally renowned radiographer and specialist in the field of cineradiography or moving image X-ray films. While still at school, he – with the assistance of his GP father John Reynolds – constructed a fully functioning X-ray machine just months after German scientist Wilhelm Röntgen first described the ‘new type of ray’ in late 1895.

Keen amateurs in Britain were quick to replicate Röntgen’s spectacular experiments using a combination of shop bought and home-made equipment. Fifteen-year-old Russell was particularly well-placed, being the son of a medical doctor and family friend of physicist William Crookes, inventor of the Crookes tube (the early electrical discharge tube used to produce the first X-rays).

John and Russell constructed one of the core components of their machine – the spark induction coil – themselves, documenting the process in the English Mechanic, a popular science magazine pitched at technology enthusiasts. This photograph of the 13-inch coil is very similar to the one featured in the article, published on 11 February 1898.