How to make a bra out of two handkerchiefs, c1921

How to make a camisole (in fact an early bra) out of a pair of handkerchiefs. British Pathe now have this as a streaming vid on their website: It may be similar to the one made by the New York socialite, Mary PhelpsJacob, later patented by her, with a more complex form in 1914. Almost certainly the model wears it over her shift for reasons of cinematic propriety. British Pathe archivist dates it to around 1921.