During the late eighteenth and early nineteenth centuries, the American Philosophical Society regularly received letters, and occasionally full blown manuscripts, from members of the public regarding their ideas on science or technology. In 1829, Edward Mulhern of Philadelphia submitted a manuscript on terrestrial magnetism that he felt had implications for navigation. Little is known about Mulhern other than that he died before 1833. Mulhern's "Dissertation on the doctrine and principles of magnetism &" is an attempt to work through some fundamental issues in terrestrial magnetism, including the relative orientation and positions of the geographic and magnetic poles, with an eye toward their impact on navigation. The APS Minutes for April 15, 1833, read: "An application from Alex Mulhern to have returned to him a paper on the 'doctrine of Magnetism' laid before the society by his deceased father, was received and the Librarian was directed to return the same.'"