The International Atlas of Clouds and of States of the Sky by the Office National Météorologique, 1930s

“Ho! Ho! Ho! To the bottle I go
To heal my heart and drown my woe
Rain may fall, and wind may blow
And many miles be still to go
But under a tall tree will I lie
And let the clouds go sailing by”

— J.R.R. Tolkien, The Fellowship of the Ring

 

 

Around the beginning of the 19th Century, there was a fashion for cloud atlases. Their rise was most likely linked to the age’s spirit for adventure, when industrialisation was making the world smaller and travel by hot-air balloon offered humanity a god-view. But you can only see the world below if the weather is right. So predicting the weather became increasingly important, and that meant understanding clouds.

And we are still learning about them. For instance, during early summer in the northern hemisphere, you might spot noctilucent clouds (NLCs) shining against the night sky. Appearing about 30 minutes after sunset in the west, NLCs are the highest known clouds that form in Earth’s atmosphere, existing at an altitude of around 50 miles (80km). But we don’t know how they form. Scientist think they’re made from ice crystals, but can’t explain how the water molecules reach so high in the atmosphere.

In the 1930s, the Paris-based Office National Météorologique published its International Atlas of Clouds and of States of the Sky. Used to educated weather forecasters and meteorologists,the atlas contains detailed descriptions and images of different types of clouds, with reference to their height, shapes, rarity, their behaviour and a view of the weather the clouds indicate.

 

 

More clouds atlases:

Know Your Clouds 1966: An Animated Appreciation Of Changing Skies

How To Recognise Clouds – The International Cloud Atlas, 1896