Have you ever looked at the sky and wondered just what that shade of blue is? A cyanometer is an instrument that lets you measure the blue of the sky. It was invented in 1789 by Swiss physicist Horace-Bénédict de Saussure. He created it from 53 squares of paper dyed with Prussian Blue, ranging from white through blues to black. The papers were then arranged on a wheel, to make it easy to hold the cyanometer up to the sky and find a colour match. He took his instrument on hiking trips to Geneva, Chamonix and Mont Blanc, and from his observations deduced that the colour of the sky was dependent on the amount of suspended particles in the atmosphere.
Although the cyanometer may look somewhat unsophisticated, the very idea of a device to measure something so ephemeral and poetic as the blue sky has captured the imagination of artists and writers ever since. Byron joked about a similar instrument to measure bluestocking women, and you can see the simplicity of ever-deepening shades in the simple scales of Miles Davies classic Kind of Blue. Here at The Chromologist we featured a student at Yale who had created her own version while studying a course there on the colour blue.
If you want to make your own it couldn’t be easier. A very simple solution is to use a paint colour card – if you have the time to cut it up and arrange the blues from light to dark so much the better. You want to hold the card up to the sky, facing away from the sun, so that you can find the best match. As the above cyanometer shows though, they make a lovely object in themselves, so for instructions on how to create one from scratch with just some card and some watercolour paint, try this easy method from the web: How to make your own cyanometer