The smoking cap in the 19th-century male wardrobe and its purpose

Velvet caps like these, with embroidery and rich decoration, were a common item of the male wardrobe in the nineteenth century. To the modern eye, admittedly, they look somewhat odd. But the headgear served no merely decorative purpose: this is the so-called smoking cap, worn in smoking rooms or at gentlemen's gatherings over a cigar, so that the hair should not smell of tobacco. How much water I might have saved, had I known of this cap some ten years ago!