3 3 c m
40cm
actual image size: 32cm x 25cm
Description
This was a portable instrument that could be used to measure the apparent speed of clouds, giving an insight into the state of the upper atmosphere. The pointer was lined up with the cloud so that the reflection of the cloud could be seen in the black glas surface. The carrying case doubled as a stand.
Image Details
Image Ref.
10313158
© Science Museum / Science & Society Picture Library