BIOLOGICAI^ SURVEY OF WOODS HOLE AND VICINITY. 



41 



Tables 1 and 2 show the temperature ° and density conditions encountered during 

 the August observ^ations. Chart 211 represents the surface and bottom temperatiu-es 

 for each station, the figure used being in each case the earliest one taken. The following 

 generalized statements may be made regarding these figures: 



(i) The greatest extremes of temperature recorded are 71.5° and 55.0°, giving 

 a range of 16.5° within the limits of the region. 



(2) The surface temperatures average 2.21° higher than the bottom temperatures, 

 the dififerences increasing as we pass toward the western end of Vineyard Sound and 

 the lower end of Buzzards Bay. The mean figures (based upon all the figures of the 

 tables) are surface 66.04°, and bottom 63.83°. 



(3) Buzzards Bay contains warmer water than Vineyard Sound, the mean figures 

 being 67.93° (surface) and 66.19° (bottom) for the Bay, and 64.70° (surface) and 62.28° 

 (bottom) for the Sound. 



(4) In both Vineyard Sound and Buzzards Bay, both at the surface and the bottom, 

 there is a steady decrease in temperature as we pass from northeast to southwest; i. e., 

 toward the open ocean. 



In Buzzards Bay the maximum surface temperature (71.5°) was found near the 

 head, while the minimum (64.8°) occurred off Cuttyhunk. The maximum bottom 

 temperature also occurred at the head of the Bay, where surface and bottom waters 

 were practically of equal warmth. A minimum of 60.2° was found oft' Cuttvlumk, 

 just at the mouth of the Bay. 



We have ver>' reluclanth" decided to employ the Fahrenheit scale in the present work, for the following reasons: Our in- 

 struments, and practically all those in use by the Bureau of Fisheries, are graduated in this scale. Moreover, in past .\merican 

 hydrographic work temperatures have usually, if not always, been expressed in Fahrenheit dejirecs. We should, however, have 

 employed the centigrade scale, despite the foregoing considerations, were it not for the fact that our temperature charts were 

 drawn before due consideration was given to this matter; and il does not seem worth while to change them now, particularly 

 as plates have already been prepared from some of Ihem. For the convenience of those who are more familiar with the centi- 

 grade scale we append a conversion table: 



Table for Conversion of F.^hrenheit to Centigrade Degrees. 



