Protractor and parallel rule combined
1740-1750
Brass 18-inch rolling parallel rule with adjustable line spacing device
1866-1876
Parallel rule, Southern Railway
Rolling type of Parallel rule with octagonal ends
1907
Parallel rule and protractor with index arm
1865-1875
Ivory plotting scale opens to rolling parallel rule and contains dividers and combined pen and pencil
Naval parallel rule
1882-1887
Sliding parallel rule
Rolling parallel rule by Stanley in brass
1900-1930
Capt. Field's Improved RAF navigator's parallel rule by Dargue Brothers Ltd., 1939
1939