Barlow’s models
A three-dimensional picture enlivens a thousand words
One of my favourite websites is the Internet Archive, a marvellous repository of old books, movies and audio recordings. As I prepare Classic Kit each month I regularly find myself grazing my way through their collection of textbooks and monographs. What is striking is the sheer aridity of old chemistry texts, featuring just a few pictures of apparatus. It is small wonder that chemistry lecturers required huge wooden benches festooned with apparatus and chemicals to bring alive what was then a pretty abstract subject.
Our textbooks today are awash with photos, diagrams and visualisations. So what are the key images that really kickstarted the process of making the invisible atomic world almost tangible?
When John Dalton reignited the dormant atomic theory at the beginning of the 19th century, he accompanied his hypothesis with a set of rather cryptic symbols – circles with lines, crosses and stripes – to distinguish one atom from another.