2 Antique QUEEN & Co PHILIA 18" Brass Parallel Slide Ruler Nautical Drafting

Description

2 Antique QUEEN & Co PHILIA 18" Brass Parallel Slide Ruler Nautical Drafting.
2 amazing antique brass slide rules. Both made by Queen & Co but one stamped "Philia" and the other stamped "Philad". Early 1900s making in Philadelphia.
Both measure 18" and have bevel edges on either side. The wheels move the slide evenly. Very well built and and very rare items!
Not sure if these were nautical or regular drafting tools...
The one is missing a screw from the bottom, see pics.