EXPLANATION OP OCEAN TEMPERATURE CHART No. 29. ^ 



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

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

 1884. 



Higher temperatures than ."iS^ were recorded at Petit Manan, but not at Mount Desert Rock and Matinicns Rock. 

 The isotherm of 60° extends north continuously only to Nantucket New South Shoal, 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 Tortngas several times during the year and reached 80° only between 

 October 24 and 29, 



