Volumetric Flask: a Bulb Blown on a Tube, Marked by the Weight of Water (Shenstone, 1916)

A volumetric flask is a round bulb on a long narrow neck with one line on it: filled to the line, it holds a known volume. W. A. Shenstone's The Methods of Glass-Blowing (1916) gives each part: how to gather the glass at the end of a tube and blow it into a bulb, how to etch a line through wax with hydrofluoric acid, and that grams of water at 4 C give the volume in cubic centimetres. Where the line goes is found by weighing in water; that use of his rule for a flask, and the tools, are ours. Source: W. A. Shenstone (1916), pp. 47-49, 70-74, 76-78. Picture: his pp. 47-48 with Fig. 20.