Public domain photos

The image shows a wooden box with a white surface on top of it, containing a variety of glass objects. The glass objects appear to be radiometers, which are used to measure the amount of light emitted from a source.

The image shows a wooden box with a white surface on top of it, containing a variety of glass objects. The glass objects appear to be radiometers, which are used to measure the amount of light emitted from a source.Open in library