These images are from the book How to Develop a Powerful Grip by Edward Aston, a legendary strongman who was famous in the early twentieth century for performing feats of strength that involved his incredibly powerful grip. The first image on the left, Gripping an Open Door, is used to develop pinch grip strength and the second, Hanging from a Rope, is one of the best exercises there is for improving your grip, according to Aston.

Source: rosstraining.com