I personally find drawing circles and spirals a great way to practice mindfulness and was originally inspired to do this by the Art of Imperfection Creative Journal.

Brunel used drawing circles to test the smoothness of the railways. “In 1833 Brunel, aged 27, was appointed engineer for the newly proposed GWR… Brunel planned to build a smooth flat and fast railway from London to Bristol. Even before he became the GWR’s engineer he travelled on other railways drawing circles in a notebook to test their smoothness.”

At the Being Brunel Museum in Bristol, you can “ride” the railway and do your own test of drawing a perfect circle (electronically). You can also see a large collection of his notebooks including the one pictured above.