134 



at the mouth of this river there is a mean for the Summer of six 

 inches of rain, and an annual mean of seventy-eight inches. At 

 Sitka, as shown by the Alaska Coast Pilot, from a record kept from 

 eighteen hundred and forty-seven to eighteen hundred and fifty-four, 

 and from eighteen hundred and fifty-five to eighteen hundred and 

 sixty-four, the annual mean is eighty-two and sixty-six one-hun- 

 dredths inches. For the purpose of ascertaining the effect on our 

 climate of that branch of this gulf stream where it passes down our 

 coast, I procured from Captain Bradbury the logs of twenty-four voy- 

 ages of the Occidental and Oriental Company's steamers between 

 San Francisco and Yokohama. These voyages were between Novem- 

 ber sixteenth, eighteen hundred and seventy-five, and December 

 twenty-sixth, eighteen hundred and seventy-six. From these I have 

 gathered the temperature of the air and water, taken at noon, for 

 a distance of nine hundred miles west from San Francisco, and the 

 temperature of the water for the same distance east from Yokohama, 

 Yokohama and San Francisco being very nearly in the same lati- 

 tude. These distances were selected on each side of the ocean, 

 because there is no marked increase or decrease in temperature 

 either near San Francisco or Yokohama, until these distances have 

 been passed. There has also been gathered the temperature of the 

 water in miclocean between these two points ; one series for each 

 month at about latitude forty-two degrees and longitude one hundred 

 and eight} 7 degrees, and one series for each month at about latitude 

 thirty-two degrees and longitude one hundred and eighty degrees. 

 The steamers coming from Yokohama to San Francisco usually 

 going north to forty-two degrees, and the steamers from San Fran- 

 cisco to Yokohama going south to thirty-two degrees. The mean 

 temperature of the water for a distance of nine hundred miles east 

 of Yokohama for the year was sixty-five degrees and forty one-hun- 

 dredths. The mean of the warmest temperatures of the water for 

 the year was sixty-five degrees and ten one-hundredths. The mean 

 of the coldest was sixty degrees and thirty-seven one-hundredths. 

 The warmest on any day was September seventh, eighteen hundred 

 and seventy-six, seven hundred and fifty miles east of Yokohama, 

 when it was eighty-four degrees. The coldest was January four- 

 teenth, eighteen hundred and seventy-six, at the same distance, 

 when it was forty-nine degrees. 



The means of the air and water for each month for a year, for a 

 distance of nine hundred miles west of San Francisco, are as follows: 



MoXTH. 



Mean of air. : Mean of water. 



January 



February 



March _' 



April 



May 



June 



July 



August 



September 



October 



November ; 61° 25-100 61° 25-100 



December 50° 5S-100 59° 41-100 



51° 62-100 i 53° 10-100 



53° 75-100 I 54° 62-1 Oil 



54° 87-10(1 54° 75-100 



53° 50-100 50° 



57° 50-100 57° 25-100 



58° 75-100 : 58° 37-100 



62° 12-lou 60° 87-100 



64° 62° 25-100 



62° 63° 12-100 



62° 12-100 61° 50-100 



Mean fur the year 5S° 17-100 58° 04-100 



