Back to Mary Russell's World 
Technology
The Twenties were a time of enormous development in technology. Household devices—radios, refrigerators, even vacuum cleaners; cars that the middle class could afford; the conquest of some of the world’s worse diseases; you name it, the Twenties took it a mile down the road.
Links
A timeline of inventions
For a history of forensic science developments—what was available in the lab in 1915? —and a timeline
The superb London Science Museum
And near Reading, the Corps of the Royal Electrical and Mechanical Engineers have a tech museum