EXPLANATION OP OCEAN TEMPERATURE CHART No. 27. 



Isothermal lines coBDeotingthe series of light-house stations on the eastern coast of the United States represented 

 on Chart No. 1, constructed for every 5° of temperature, FsBlirenheit, from 40° to 80°, inclusive, for the year 1882. 



The isotherm of 40° extends south continuously in the spring only as far as Abaecon Inlet ; during the period of 

 falling temperature, however, the isotherm of that value extends to Body's Island. Higher temperatures than mfi 

 were recorded at Petit Manan, irom August 18 to November 8, but the isotherms of 55P begin at Segujn Island. The 

 isotherm of 60° appeared at Boon Island and Thatcher's. Island, but not elsewhere north of Viney-ard Sound, although 

 the record is incomplete for Nantucket New South Shoal. The isotherms of 65° extend north continuously to Vineyard 

 Sound, and the same temperature was also recorded at Thatcher's Island. At the Tortugas, the temperature was 

 below 75° between May 9 and 21, and below 80° between October 8 and 14. 



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