These essays have been collected and edited by the Amer. Philosophical Soc., of which Franklin was a founder, to honor the Society’s 275th Anniversary. Contents: Letter to Mr. Nairne, of London, from Dr. Franklin, Proposing a Slowly Sensible Hygrometer for Certain Purposes; A Letter from Dr. B. Franklin, to Dr. Ingenhausz, Physician to the Emperor, at Vienna, on the Causes and Cures of Smokey Chimneys; Description of a New Stove for Burning of Pitcoal, and Consuming All Its Smoke, by Dr. Franklin; A Letter from Dr. Franklin, to Mr. Alphonsus le Roy, Member of Several Academies, at Paris. Containing Sundry Maritime Observations. Illus.