The picture is captioned:
(1.) - A SQUAD OF TWO HUNDRED BOYS EXECUTING THE FIRST ARM EXERCISE.
Rather oddly, the boys are all wearing their caps.
This photograph is part of a series of activity sheets, demonstrating lessons in various British schools, in Edwardian times.
I am not sure of the history of the pictures.
They look as if they were originally in some sort of album or folder.
Perhaps they were from a teachers' manual or similar?
The photograph measures around 8" x 4.75" (20 cm x 12 cm).
It is printed on a plain sheet of paper, around (the sort that was commonly used for "book plates" in Edwardian times).
This sheet is about 12.5" x 7.75" (32 cm x 20 cm) . It has been cut (rather unevenly) along one side, presumably when it was removed from its original album or folder.