EXPLANATION OF OCEAN TEMPERATURE CHART No. 3. 



CAEYSFOJRT EEEF LIGHT:H0USE, FLOEIDA. 

 Observers: Edwaud Bell, E. A. Beost, Martin Wbathekfokd. 



Location of sJafion.— Carysfort Eeef liKht-House is located on the outer side of Carysfort Eeef, in front of Key 

 Largo, and facing the Straits of Florida. It is ahout 158 miles northeasterly from the Dry Tortugas light-house. The 

 ■water deepens rapidly from the outer edge of the reef, attaining a depth of 50 fathoms within a distance of ahout 2 

 miles. The 100-fathom curve is distaut ahout 7 miles, and the axis of the Gulf Stream about 27 miles. 



Geographical position.— hatitude, 25° 13' 15" N.; longitude, 80° 12' 42" W. 



Depth of water.- — Three feet. 

 ' Bange of temperature.— A\i, 18°.5 (65°.5 to 84°) ; surface, 15° (71°.5 to 86°.5). 



The temperature is more equable at this station than at the Tortugas, both as regards the air and water. The 

 air temperature is relatively lower throughout the year, the maximum being 4^° lower at Carysfort than at the Tor- 

 tugas. The curves of surface temperature are more regular, and are very uniform for all the years, apparently indi- 

 cating that the place at which the observations were taken was well suited for the purpose, although the depth c/ 

 water was only 3 feet. The maximum surface temperature was practically the same at this station as at the Tortugas, 

 and exceeds the air maximum by 2°.5. 



The low temperatures recorded at the Tortugas for March, 1881, and November 26 to December 6, 1882, were also 

 observed at this station, though in a relatively less degree, especially as regards the former period. During the first 

 part of March, 1881, northerly .and northwesterly winds prevailed, while during the latter part of the same month the 

 winds were variable. During the ten days ending December 6, 1882, they were mostly from the north and northeast. 



Table shoioing the direction of the loinds, hy quadrants, for each month of the 'near, being the means of jive years' observations. 



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