Someone presumably came up with the idea that making a cast of a prisoner's head was a good idea. Who that was, or why they thought that, I have no idea. Nonetheless the practice was quite common in the 1800's / early 1900's, and quite a number of them are displayed in the cells on the ground floor of the jail.

One school of thought is that it was done as an aid to the "science" of phrenology; the idea that the shape of the skull determined the behaviour of the person. Or, perhaps, vice versa.

In this case we see the death mask of George Melville, a bushranger (highwayman) who was convicted of robbery with intent to murder and hanged in 1853. I'll tell his story in his close-up in the next image.