Beginning in December, The Maryland Historical Society in Baltimore will host an exhibition titled Mason and Dixon and the Defining of America: Iconic Treasures from the Maryland Historical Society, Independence Hall and the Maryland State Archives. The exhibition will display a wealth of historical documents, including the articles of agreement that launched the survey, Mason’s hand-written journal and the 1768 hand-drawn map signed and sealed by the boundary commissioners. Also on view will be the transit and equal altitude instrument commissioned by Thomas and Richard Penn from London’s master instrument maker John Bird specifically for Mason’s and Dixon’s use.

The exhibition will open at 6 p.m. on Tuesday, Dec. 3, with a preview reception and lecture by David S. Thaler, PE, LS, F.ASCE, F.NSPE, vice president of the Maryland Historical Society Board of Trustees and chair of the Board’s Library Committee. Registration is required, and tickets cost $50. The exhibition will be open to the public at regular admission rates from Dec. 4, 2008 to Feb. 28, 2009.

For information or to register for the reception, call 410/685-3750 ext. 321, e-mail abeiter@mdhs or visit www.mdhs.org.