70 



Ruschenberger.] * u [May 15, 



Dr. Emerson was chosen to be a member of the American Philosophi- 

 cal Society, April 19, 1833. At stated meetings he made many brief com- 

 munications on many subjects, which are recorded in Vol. i to Vol. xvi 

 of the published Proceedings.* 



He was one of the Councilors of the Society during ten years, from 

 1837 till the end of 1846. 



He delivered a lecture On the Advantages Derived from Cultivating the 

 Arts and Scienas, before the Philadelphia Mercantile Library Association, 

 in the hall of the Musical Fund Society, December 8, 1839. 



Among other points of interest, he states that the first successful attempt 

 to cross the Atlantic in a vessel propelled by steam was made in a steam- 

 ship called the Savannah, commanded by Moses Rogers, a native of Con- 

 necticut, but long a resident of Philadelphia. He sailed from New York, 

 March 28, 1819, and arrived at Savannah, Ga., April 6, whence, after some 

 delay, he crossed the ocean and arrived at Liverpool, June 20, having used 

 steam or sails, as the wind permitted. From Liverpool the Savannah 

 went to Elsineur, Stockholm, Cronstadt, St. Petersburg and Copenhagen. 

 She then returned to Savannah, Ga., and thence went to Washington, 

 D. C. Thus the practicability of crossing the Atlantic in a vessel propelled 

 by steam was first demonstrated by an American. 



In this connection he relates how Thomas Godfrey, an obscure citizen of 

 Philadelphia, from a casual observation of the reflection of light, perceived 

 the principle upon which he constructed, in 1730, the mariner's quadrant, 

 and how he was robbed of the credit of his invention, and claims that 

 Godfrey is entitled to "the lasting gratitude of all concerned, either di- 

 rectly or indirectly, in nautical pursuits, by inventing the only instrument 

 that can securely guide the ship when far from land," and they should 

 not permit only " a fragment of the most perishable stone " "to mark but 

 for a few years longer the grave of Godfrey." 



This appeal induced members of the Mercantile Association and others 

 to construct a suitable monument to Godfrey's memory. 



* The subjects upon which he made oral or written communications are as follows : 



The production of electricity from the animal body ; the production of electricity 

 from steam ; observations on Mower's paper on meteorology; excessive mortality of male 

 children ; effects of hot weather on infants ; causes operative in changing the propor- 

 tions of the sexes at birth ; importance of phosphoric acid in agriculture ; phosphores- 

 cent light produced in the diamond by friction ; the compound action of the mental 

 and optical faculties concerned in vision ; cultivation of cotton in the Northern States ; 

 cleaning flax-fibre for market ; extent of propagation of atmospheric vibrations produced 

 by explosions of powder ; manufacture of the sugar and syrup of sorghum ; iniphse, 

 or African sugar cane and cultivation of sorghum ; improvements in Whitney's cotton 

 gin ; Robbini's process for preserving wood from decay by injecting into it vapor of coal 

 tar ; remarks on the part taken by the American Philosophical Society in connection with 

 the Franklin Institute, to establish stations for meteorological observations ; earthquake 

 of October 20, 1870, reported November 4, 1870, as to expanse over which shocks were 

 noted ; lunar influence on wet and dry weather ; ascription of the gradual translation 

 of the peach-tree belt southward on the Atlantic coast to the progressive removal of the 

 forests, causing exposure of the fruit trees to severe climatic fluctuations. 



