6 



BULLETIN 55, UNITED STATES NATIONAL MUSEUM. 



voyage, and eight on the return voyage, distributed at nearly equal 

 intervals over the twenty-four hours. 



The following table presents the results of certain computations 

 from the official records. (All temperatures are given in degrees 

 Fahrenheit.) 



Temperature of air and surface water. 



It will be seen from the above table (1) that the average temperature 

 of the air, in these regions uninfluenced by the proximity of other 

 than small and scattered islands, varies little from that of the contig- 

 uous waters of the sea. (2) That in the region between the Hawaiian 

 Islands and Guam the difference between summer and winter temper- 

 atures of both air and water is quite small. On the round trips 

 between Guam and Luzon and Guam and Yokohama, each having 

 occupied only about two months, there are not sufficient data for esti- 

 mation of seasonal changes in these regions. In considering extremes 

 of temperature, it should be remembered that Midway Islands and 

 Yokohama are both in considerably higher latitudes than the Hawaiian 

 Islands, Guam, and Luzon, and, other conditions being equal, the low- 

 est temperatures would naturally be found in the higher latitudes. 



Thus, the surface temperature in the vicinity of Oahu is about 

 75^.4, while in the vicinit}^ of Midway it falls to about 71°. Leaving 

 Midway with an average of 70^^.4 at the first eleven stations, the sur- 

 face temperature rises to an average of 84°. 8 at the last thirty-one 

 stations approaching Guam. From Guam until within 300 miles of 

 Yokohama the surface water remains near 85°, falling to an average 

 of 76°. 7 at the last eighteen stations. 



The diurnal variations of temperature were of course greater in the 

 air than in the water near the surface. The normal range of variation 

 was from 4° to 7° for the air, and 1° to 3° for the surface water. The 



