Most anachronism activities used in schools are the rather naff ones put before Y7 pupils in an introduction to What is History. You know the sort of thing: Roman soldiers wearing wrist watches.
This activity is different. Whilst based on a single image, it is set in a very specific moment in time i.e. 1796 when Jenner is demonstrating his inoculation technique. Around him are other figures in a hospital setting. Lurking in the picture are 10 deliberate mistakes, some of which are quite subtle. So you have mid-19century pieces of medical equipment which would have been unknown to Jenner.
Having spotted the 10 anachronisms- even more fun if you make it a competitive starter- students then have to find, also in the picture, the 10 objects/methods that WOULD have been used by Jenner.