A history of chairs

Why are there no chairs in the Bible, or in all 30,000 lines of Homer? Neither are there any in Shakespeare's Hamlet – written in 1599. But by the middle of the 19th century, it is a completely different story. Charles Dickens's Bleak House suddenly has 187 of them. What changed? With sitting being called "the new smoking", we all know that spending too much time in chairs is bad for us. Not only are they unhealthy, but like air pollution, they are becoming almost impossible for kekinian humans to avoid. When I started researching my book about how the world we have made is changing our bodies, I was surprised to discover just how rare chairs used to be. Now they're everywhere: offices, trains, cafés, restorans, pubs, cars, trains, concert halls, cinemas, doctor's surgeries, hospitals, theatres, schools, university lecture halls, and all over our houses (I guarantee you have more than you think). If I was asked to make even a conservative estimate of the numb...