PHYSICAL INVESTIGATIONS OFF THE NEW ENGLAND COAST. 
399 
DISCUSSION OF THE RECORDS. 
MANNER OF KEEPING THE RECORDS. 
The observations were recorded in a book especially prepared for this work, in 
which four pages were allotted to each day’s work. The first page was devoted to the 
meteorological record for the 24 hours and was divided as in the appended tables. 
The second page was devoted to the record of serial-temperature and density observa- 
tions; the third page was reserved for general observations of a scientific nature, and 
the fourth contained an abstract of the log. This record book was placed in a box 
upon the top of the deck house, and the box was so arranged that observations could 
be recorded in the book at all hours and in all sorts of weather without exposing the 
records to the risk of blurring. The top of the box was glass and had a slight inclina- 
tion away from the observer, in order to throw the rain in that direction. The side next 
to the observer (with the exception of a 2-inch strip of wood at the bottom) was can- 
vas, with two holes in it opposite the center of each page in the record book. Through 
these the hand was passed in making the record. These openings were covered when 
the box was not in use by a flap of canvas which could be securely buttoned down 
over the end of the box. The glass top was also covered with a flap of canvas to pro- 
tect the rulings of the book from the action of the sunlight. At night the interior of 
the box was illuminated by a lantern placed at the left end. 
THE METEOROLOGICAL RECORDS. 
July 24, 1889. (Table 1 and Plate 1.) — We commenced work upon line A, south 
of Nantucket. (See map.) The air curves (Plate 1) of the temperature of New York and 
Boston follow one another very well, the effect of more northerly latitude being seen 
in the much lower depression of the curve when there is a decline in the temperature. 
The decrease in temperature on the Grampus in the a. m. is probably due to the 
influence of the water, as we were leaving shoal and inshore waters, which were warm, 
and passing through cold surface water until 11 a. m., when we reached much warmer 
water. This will be clearly seen from the curves on the same plate, which contrast 
the temperatures of the air and water for the same day. 
The maximum air temperature on the Grampus is reached at 3 to 4 p. m., and 
seems to show an utter disregard for the disturbance which is going on upon the land. 
There is a long steady decline until 10 p. m. The sudden rise at this point can be 
again explained by reference to the curves of the air and water temperatures, the 
water curve being particularly instructive. After the lowest surface temperature was 
reached at 11 a. m., there was a rise in the water temperature of 4° F. each hour for 
2 hours, a change which could hardly be due to the sun’s intluence in so short a 
time. Of course the air temperature was somewhat modified by this condition of the 
water. It will also be seen from the records that there was a decided increase in the 
specific gravity of the water (1.0241 to 1.0249 and 1.0253). The effect of the warm 
midday sun upon a body of water which originally had the same temperature is seen 
from the curve between 1 p. m. and 5 p. m., where its gradual cumulative influence is 
apparent, although the temperature of the air at the same time had commenced to fall, 
and the decrease in the surface temperature after 5 p. m. is probably due to the with- 
