Sun valve

Sun valve

C014/1500 Rights Managed

Request low-res file

530 pixels on longest edge, unwatermarked

Request/Download high-res file

Uncompressed file size: 25.4MB

Downloadable file size: 1.7MB

Price image Pricing

Please login to use the price calculator


Credit: NEW YORK PUBLIC LIBRARY/ SCIENCE PHOTO LIBRARY

Caption: Sun valve (upper left) on a routing beacon. A Sun valve consists of a central blackened metal rod, surrounded by three polished rods, all enclosed in a glass tube. When the Sun rises the blackened rod heats up and expands to become slightly longer than the polished rods. The expansion triggers a device to shut of gas flow to the beacon. As the Sun sets the blackened rod contracts, starting the flow of gas again. The Sun valve was invented by the Swedish industrialist Gustaf Dalen in 1907, initially for use in lighthouses. Photographed in the USA.

Release details: Model release not available. Property release not required.

Keywords: american, beacon, black-and-white, control, dalen light, daylight, device, engineering, flow control valve, gas supply, glass tube, gustaf dalen, historical, history, light, monochrome, north america, people, person, routing beacon, sun valve, technological, technology, united states, usa, valve

Licence fees: A licence fee will be charged for any media (low or high resolution) used in your project.