VI.-TABLES OF TEMPERATURES OF AIR AND WATER AT 

 SUNDRY STATIONS OF THE UNITED STATES SIGNAL OFFICE, 

 FROM MARCH, 1874, TO FEBRUARY, 1875, AND FROM MARCH, 

 1876, TO FEBRUARY, 1877, INCLUSIVE. 



lu view of the great importance of accurate data iu regard to the 

 varying temperature of the water of the rivers and lakes of the United 

 States, in connection with the introduction of different kinds of new 

 fishes, application was made to Brig. (jen. A. J. Myer, chief signal-officer 

 of the United States Army, to cause observations on this subject to be 

 made by the persons attached to his service and distributed throughout 

 the United States. With his usual readiness to render all possible aid 

 to scientific and practical inquiry. General Myer caused blanks to be 

 prepared for the record of the observations in question, and forwarded 

 them, with a suitable thermometer, to the various stations, and has since 

 sent copies of the returns to the office of the United States Fish Com- 

 mission. 



The first of the two Wood's Hole, Mass., series of observations has 

 been kindly furnished by the Light- House Board. 



These returns for two years, from March, 1874, to February, 1875, and 

 from March, 1876, to February, 1877, have been reduced and digested 

 by Mr. H. Jacobson, and are herewith appended. They show the re- 

 sults of observations at fifty -four stations, respectively, and give tables 

 of the mean temperature of the air at 3 o'clock p. m. for each month, 

 the mean temperature of the water at the bottom of the stream at 3 p. 

 in., as also the absolute maxima and minima of the bottom temperature 

 for the same period. 



These records are more or less imperfect, and must not be taken as 

 being more than an approximation to the actual condition of the water 

 during the period mentioned. 



SPENCER F. BATED. 



851 



