Per Jack's suggestion... 
It almost seems odd in this modern high tech world that so many things are still valued and sold by size or weight. From food to fuel to building materials, scales and rulers are not obsolete yet.
Knives have been around forever and it isn't a stretch to think that rulers have accompanied them since early on. It is known through "Smith's Key" from 1816 that a knife with a ruler on the handle existed over 200 years ago in England. Certainly, knives with rulers incorporated were in existence long before that. In the late 19th and early 20th centuries, all metal ruler knives were fairly popular and were produced by several Sheffield cutlers. Since then, many unique ruler knives have been produced by various cutlery companies from around the world. Enclosed are a few examples and please feel free to add more.

Catalog cut from "Smith's Key" 1816

Ibberson ruler knife, Sheffield c. 1920s - 1930s

Newton of Sheffield catalog cut

CEM (Cellini Espero Maniago) Italian metal rolling ruler (tape measure) c. 1960

It almost seems odd in this modern high tech world that so many things are still valued and sold by size or weight. From food to fuel to building materials, scales and rulers are not obsolete yet.

Knives have been around forever and it isn't a stretch to think that rulers have accompanied them since early on. It is known through "Smith's Key" from 1816 that a knife with a ruler on the handle existed over 200 years ago in England. Certainly, knives with rulers incorporated were in existence long before that. In the late 19th and early 20th centuries, all metal ruler knives were fairly popular and were produced by several Sheffield cutlers. Since then, many unique ruler knives have been produced by various cutlery companies from around the world. Enclosed are a few examples and please feel free to add more.

Catalog cut from "Smith's Key" 1816

Ibberson ruler knife, Sheffield c. 1920s - 1930s

Newton of Sheffield catalog cut

CEM (Cellini Espero Maniago) Italian metal rolling ruler (tape measure) c. 1960