EXPLANATION OF OCEAN TEMPERATURE CHART No. 25. 



PETIT MANAN LIGHT -HOUSE, MAINE. 

 Oheerver : George L. Upton. 



Looation of station,.— Petit Manau light-liouse is located on tlie southernmost of a group of low, rooky islets, known, 

 collectively, as Petit Manan Island. These islets are situated off the western entrance to Pigeon Hill Bay, near 

 Gouldsborough, Me., and are distant about 2 miles from the nearest point of the mainland. They are immediately 

 surrounded by ledges and shoals, but within a distance of 8 miles to the southward depths of 60 fathorns occur. The 

 light is 27 miles NE. J N. from Mount Desert Eock light-house. 



GeograpUoal position.— Ijatitxiae, 44° 92' 03" N. ; longitude, 67° 51' 51" W. 



Depth of water. — Eight to 15 fathoms. 



Bange of temperature (March 1 to January 1).— Air, 50" (20° to 70°); surface, S7°.5 (31° to 58°.5). 



The range of air temperature is the same as at Mount Desert Eock, but with the maximum and minimum temper- 

 atures each 5i degrees lower. Excluding the year 1883, the maximums of air temperature would be nearly the same 

 at both places. The surface maximum is 4 degrees higher at this station. The surface curves for 1881 to 1883, incln 

 sive, are fully as irregular as at Mount Desert Rook, and there is the same lack of uniformity between the different 

 years, but the variations do not in any way correspond at the two stations, and the conditions by which they were 

 produced were evidently not common to both. There is much greater correspondence between the years 1884 and 

 ISS.'-i. 



Table >,hoti;ing Ike direction of the winds, hy quadrants, for eacTi montli of tlie year, heing the means of five years' observations. 



Qnadraut. 



JTortbcist 



Southeast 



Southwest — 

 Northwest 



January. 



5.5 



9.5 



12.4 



Fehiu- 

 ary. 



5 

 

 7.3 



March. 



8.C 



9.2 

 7.2 



April. 



5.7 

 10.7 

 6.8 



May. 



10.5 

 8.4 

 3.0 



June. 



3 7 

 11.1 

 11.8 



3.4 



July. 



3 



14.3 

 11.4 



1.8 



Auf^ust. 



3 8 

 13.0 

 11.3 



2.3 



I 



Septem- 

 ber. 



5.5 

 9.2 

 10.9 

 4.3 



Octoher. 



5.0 

 8.9 

 7.4 

 9.1 



Kovem- 

 ber. 



6.4 

 6.3 



Decem- 

 ber. 



4.3 

 7.2 

 7.9 

 11.6 



224 



