400 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
drawal of this iiiiiaeace. At 22 hours (or 10 p. m.) a band of still warmer water was I 
reached, which also had a high specific gravity, and its influence is instantly noticed 
in both air and water temperature curves. The temperature of the air, with a per- . 
fectly clear sky, would naturally have decreased at this time of the night had it not r? 
been for the increase of temperature in the water. In 
July 25, 1889. (Table 2 and Plate 2.) — From the point reached at midnight the 'i' j 
temperature of the water increases in general until noon, from which time it decreases | \ 
gradually. The efiect of a heavy rain squall is noticed at 7 a. m. in the fall of the air ^ ; 
curve, and also in the arrest of the upward tendency of the water-temperature curve. 
Two rainfalls in the p. m. keep the air curve well below that of the water. The same ft' 
eftect is noticeable in the contrasts of the three air curves for the p. m. Little was 
done in the forenoon of this day owing to an accident, but in the afternoon and even- iv 
ing, finding we had drifted to the westward, we started upon the line 0, returning 
toward the shore. 
July 26, 1889. (Table 3 and Plate 3.) — We were well upon our return trip on line C. 
The high temperature of the air was probably due to warm water, a heavily overcast 
sky, and almost no wind. These conditions were reversed at noon by a fog springing 
up, followed by a freshening breeze from the east. Similar conditions seem to have 
prevailed on the laud, as shown by the air curves. The decrease in the temperature «« 
of the water as we left the warmer and more dense bands of water and approached 1 i| 
the shore is quite evident. 1 ! 
The next few days were spent in Wood’s Holl, making some changes in our appa- 1 
ratus which this trial trip had shown to be necessary. .i| I 
August 1, 1889. (Table 4 and Plate 4.) — We started outward upon line P. The ; ' i 
effect of strong wind currents is seen upon the maximum portions of all the curves. On j | 
the Grampus the wind was strong (5) at the hours 14, 17, and 19, and was from the SSW. I 
Its result was naturally first evident upon the New York curve, and a little later upon f 
both the curves of the Grampus and of Boston. The coincidence of the times and the || 
directions in these latter curves is quite striking; the rebound in each temperature || 
curve after the gust of wind had passed is a pronounced one in each case, particularly || 
so in the Boston curve at 14 hours, where the land midday temperature reasserts itself ' |j 
most decidedly. The water curve shows an increase in temperature throughout the | 
day and well into the night. The warmer temperature of the air can only be account- | 
able for a small portion of the increase at midday. | 
August 2, 1889. (Table 5 and Plate 5.) — Early this a. m. (4 hours) the water I 
became too rough to allow us to prosecute our regular work to advantage, so we n 
headed for the shore, which we sighted about 10 o’clock. Then a line was commenced m 
parallel with the coast towards Block Island, and four stations were made upon it w 
before we ran into Block Island Harbor for the night. « 
I have failed to find an adequate cause for the decrease in the temperature of the « 
water upon this line as we passed the entrance to Vineyard Sound and Buzzard’s Bay M 
(11 to 13 hours), and again as we passed across the entrance to Narragansett Bay H 
towards Block Island (17 to 18 hours), unless the tides have some eftect upon the 
local temperature through changes produced in position in water masses. In the K 
first instance it was just high tide; and in the latter, low tide. The effect upon the B 
air temperature, with an overcast sky, of strong gusty winds is seen at 11, 13, and 16 i 
hours, and this curve is in marked contrast with the air curves at New York and Boston. , I 
