Demonstration on 18th century surveying to be presented at fort

The art of 18th century surveying will be on display at the Fort de Chartres State Historic Site on Saturday, May 12 from 10 a.m. until 2 p.m.

As part of the Les Amis du Fort de Chartres Art de Vivre Series, William Rudolph will demonstrate how to work with a compass to obtain bearings, and a Gunter’s chain (surveyor’s chain) to measure distances. After collecting data, the information will be transferred to paper using scales, dividers and protractors to produce the beginnings of a map.

Everyone in attendance is invited to participate, including use of a compass and measuring distance with the chain. A plane table will also be used as part of the demonstrations. A plane table is a device used in surveying to provide a solid and level surface on which to make maps. Event participants will help produce an elevation of the fort’s gate.

The event is free and open to the public. For event information please visit or contact

Fort de Chartres State Historic Site is located at 1350 State Route 155, Prairie du Rocher. For site information, phone 618-284-7230.