Surveyor's Vernier Compass
"Edmund Draper 468 Philada"
length 15.25 inches; needle 5.5 inches
This compass was made by Edmund Draper in Philadelphia, and dates from around 1876. It has a variation arc on the north arm that extends 28 degrees to either side; the vernier is moved by rack and pinion, and reads to 5 minutes. There are two spirit levels on the south arm.