EXPLANATION OP OCEAN TEMPEHATtTRE CHART No. 29. 



Isothermal lines connecting the series of light-house stations on the eastern coast of the United States, repre- 

 sented ou Chart No. 1, constructed for every 5° of temperature, Fahrenheit, from 40° to 80°, inoliisiTe, for the year- 

 1884. 



Higher temperatures than ."15° were recorded at Petit Manan, but not at Mount Desert Eock and Matinicus Rock. 

 The isotherm of 60° extends north continuously only to Nantucket New South Stioal, but the same temperature was 

 recorded at Boon Island. Breaks of a similar character also occur in the isotherms of 75° and 80° at the southern' 

 stations. The temperature fell below 75° at the Tortugaa several times during the year and reached 80° only between 

 October 24 and 29. 



833 



