Graphic illustrates the use of the Leroy lettering devise. The pen (S) was the predecessor to the Rapidograph (i.e. priming pin facilitates ink flow).
Leroy Lettering
Periodic table - Wikipedia
Leroy lettering set N3245 manufactured by Keuffel & Esser Co., ca. 1941-1950. - Template, Lettering
K&E Keuffel & Esser Leroy II Lettering Set Amazing condition - and some extras
Trying Out The Leroy Lettering Kit
K&E LEROY Lettering Set 1950 Keuffel & Esser Drafting Kit in Wood Case
Mechanical lettering
My father-in-law just gave me his Leeroy k&e lettering set that he bought in the early 70s. It is a very interesting way of drawing perfect letters and I can't wait to
DRAFTINGEQUIP
K&E Leroy Lettering Set
K&E LEROY Lettering Set 1950 Keuffel & Esser Drafting Kit in Wood Case