192 
in position long enough to permit the meagre yet valuable 
information it can produce to be made public. 
INVESTIGATION OF TEMPERATURES. 
It was intended that a self-registering thermometer should 
be placed on each hurdle, and that the temperature to which 
the young were exposed should be noted at each examination. 
Fortunately, considering the fate of the hurdles, the ther- 
mometers were not received in time to be used, as was in- 
tended, and after the disappearance of the spat collectors it 
was not considered advisable to expose the thermometers to 
the same risks. 
About the last of July, however, I had the temperature of 
the surface water recorded every two hours, and considering 
that there is probably but very little variation of those limits 
in the Sounds, I have plotted the accompanying curve of maxi- 
mum and minimum temperatures from July 29th to October 
1st. 
It will be seen that these curves are very irregular, and that 
the greatest irregularities occur during the month of August, 
and that the greatest difference is between the 6th and 10th 
of August, one of 15° in four days. On the 15th there is a 
change of 8°, and on the 28th of 12°. 
About the 4th of August I determined to utilize the chan- 
nel buoys as marks for the positions of thermometers, hoping 
that they might thus escape the observation of those who were 
inclined to remove them. Accordingly I placed four self-reg- 
istering thermometers on the beds — one at the foot of the buoy 
on the Shark’s Fin, one on the buoy on Piney Island Bar, one 
on the buoy off Watts’ Light House, and one on the buoy off 
Sykes Island, about the middle of Pocomoke Sound. 
We were enabled to make several examinations of these 
thermometers, but about the 1st of September, finding that 
one had been stolen, I concluded to remove the others before 
they shared the same fate. 
The curves of maximum and minimum temperature given 
by these thermometers, and also the range of variation, are 
