Although unsigned, but based on the shape of the keyhole on the escutcheon and the style of the spring bow, this set can be ascertained to be of Continental Europe origin, probably made in France in the early 20th century. The instruments are made of German silver and steel, stored in a rosewood veneered mahogany case. The handle of the spring bow is made of ivory, but that of the ruling pen is of ox bone. The difference between the two materials can easily tell by a close inspection. The included proportional divider only has scales for lines. Similar to contemporary brass instruments, a pricker is concealed in the ruling pen.