An art installation with a scientific bent, the Cyanometer by Martin Bricelj Baraga is a glinting, glass and stainless-steel monolith standing in central Ljubljana. Inspired by Horace-Bénédict de Saussure’s original 1789 cyanometer – a device used to measure the blueness of the sky and thus predict the weather – Baraga’s modern, solar-powered version uses the same criteria to measure air quality.

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