LCP Minutes vol. 1, May 9, 1743, p. 133: "B. Franklin acquainted the Member Met, that he had lately received from London a Glass Concave of 12 Inches Diameter for Magnifying and burning, which he would present to the Library." Vol. 1, June 13, 1743, p. 133: "The Secretary informed that he has on the 21st of Last Month taken to the Library the Concave Mirror given by Mr. Franklin.", Gift of Benjamin Franklin, 1743.
