OCEAN TEMPERATUltES. 167 



The Florida Reefs. — ExcUidiug the observatious for the Toitugas, the extreme range of sur- 

 face temperature at the Florida Eeefs is lCo.5, with a maximum of 8G°.5. The maximum at the Tor- 

 tugas is about the same, but the minimum is 5° lower. The air temperature presents a range of 18° 

 to 210.5, the air maximum being about the same as the surface maximum at Fowey Eocks, 2o.5 

 higher at the Tortugas, and 2o.5 lower at Carj'sfort Eeef. At none of the other stations along the 

 coast do we find nearly so short a range either of surface or air temperature, and these are the 

 only stations that are situated directly within the influence of the Gulf Stream. 



South Cakolina to Virginia. — At the light-ships of Martin's Industry Shoal and Eattle- 

 snake Shoal, the range of air temperature is 41°, the surface range 38°, the maximum for the air 

 being SG°.o, the maximum for the water 85°, or about lo.5 lower than at the Florida Eeefs. The 

 greater range of temperature at these two light-ships, and at the stations immediately following 

 them toward the north is due to the much lower temperatures of winter, amounting to over 20°, the 

 differences in the maximums being slight. At Frying Pan Shoals light-ship, the maximums of both 

 air and surface temperatures are slightly lower, the air range being the same as at Eattlesuakc 

 Shoal, the surface range only 33°, with a maximum of S2°.5. The records for Cape Lookout and 

 Body's Island, show approximately the same range for both air and surface temperature at each, 

 amounting to about 42° at the former station, and 64° at the latter. 



Virginia to New York. — iforth of Chesapeake Bay the maximums of surface temperature 

 are much lower than to the south, reaching 7C°.5 at Winter Quarter Shoal light-ship, and about the 

 same at Five-Fathom Bank lightship. This is 6° lower than at Frying Pan Shoals, the first light, 

 ship south of Cape Hatteras, and about 9° lower than at Eattlesnake Shoal and Martin's Industry 

 light-ships. At the northern stations, beginning with Winter Quarter Shoal light-ship, the tem- 

 perature plottings for January and February have been omitted in most cases, and the ranges of 

 temperature, where given, are, unless otherwise stated, for only ten months. At Absecon Inlet, 

 on the mainland, the surface maximum is about 3° higher (79°. 5) than at the two preceding light- 

 ships, and agrees with the air maximum ; at Sandy Hook light-ship the surface maximum is ]i° to 

 2° lower than at Five-Fathom Bank and Winter Quarter Shoal, and 7° lower than the air maxi- 

 mum at the same place ; at Fire Island the surface maximum is S° lower than the air maximum, 

 and about the same as the surface maximum at Sandy Hook, showing more satisfactory observa- 

 tions than at any of the previous shore stations. 



Block Island to Cape Cod. — The surface maximum at Block Island is 8o..5 lower than the 

 air maximum, and onlj' 1°.5 higher (70°.5) than at the neai'est light ship, which is about 18 miles 

 distant. Brenton's Eeef and Vineyard Sound light-ships afford closely corresponding results, the 

 maximum of both air and surface temperature being slightly lower at the latter station. Tlie sur- 

 face maximum at Brenton's Eeef is G9°, being 5°. 5 lower than at Sandy Hook, 7°. 5 lower than at 

 Winter Quarter Shoal, 16° lower than at Martin's Industry, and 17°.5 lower than at («lie Florida 

 Reefs, the maximum for Brenton's Eeef being a little lower than the minimum for the Florida 

 Eeefs. At Nantucket New South Shoal, and Pollock Eip liglitsliips, the maximums of surface 

 temperature are approximately the same, about G2°, and the range of temiierature is but slightly 

 less at the former station; the air maximum is 3° higher at Nantucket than at Pollock Rsp- The 

 surface maximum is the same at these two light-ships as at Boon Island, in the Gulf of jMaino, 

 which has also approximately the same range, 29° for 10 months. This range is much sliorter 

 than at Vineyard Sound light-ship and preceding stations, while the air i-ange remains about the 

 same. The surface curves at Nantucket New South Shoal and Pollock EJp are, therefore, 

 straighter in comparison witli tlie air curves than at tlie more western stations, and Ibis same 

 feature will also be found characteristic of the stations in tlie Ijulf of Elaine. 



