Radioactivation analysis of historical artifacts provides a method for determining trace ele-ment contents in a nondestructive manner. Such precise elemental determinations are quite useful in ascertaining the age and geographical origin of the object under investigation. The principles of neutron activation analysis are discussed briefly, followed by the results of a study of a purportedly 18th century French astronomical instrument. Elemental analysis of this object, compared with those for modern brass and brass known to originate in 18th century France, indicated that it was a fraud. -- AATA