EXPERIMENTS IN HERDING SEALS. 



421 



AUGUST 18 

 HERDING SEALS. 



An experiment was made this morning with a view to determining the effect on 

 the temperature of the water in a pond or lake produced by herding a body of seals 

 in it. Three hundred and tifty seals were driven from Lukanin, where 900 seals were 

 driven from yesterday afternoon, and held four hours in the little pond beside Ice House 

 Lake. The temperature of the pond before the seals were put in was .jO° at the border 

 and 1° lower iu the middle. The pond is shallow, having an average depth of only 2i 

 feet. The seals were put in at 10.35. Below is a record of observations made with a 

 common mercury thermometer: 



Time. 



10.30 

 10.45 

 11 



11.1.5 

 11.30 

 11.40 

 12 



13.15 

 12.30 

 12.45 

 1 



1.15 

 1.30 

 1.45 

 2 



2.15 

 2.45 



Air. 



Clear 



Suusbiueand li<<;]itfog 



Light fog 



do i 54 



Sunshine and fog 



Sunshine and fog; lightbreeze.. 52 



Fog aud light breeze 54 



do 52 



Fog and breeze 53 



do ' 52 



Thick fog and light breeze 52 



do 



Thick fog. 

 Light fog . 



do 



Thick fog. 

 do 



52 

 49 



50 

 50 

 47 

 47 



Oil two occasions the temperature of a cove occu])ied by seals for half an hour 

 was taken separately and found to be 1° higher than the open water. The 

 temperature of Ice House Lake at 12.4.5 aud 2.10 was .52'^, the same as that of the 

 ponil in which the seals were. The last live observations were made by Mr. Clark ; 

 the others were made by Mr. Townsend. Mr. Clark's air temperatures were taken 

 with the thermometer wet and in the wind: Mr. Townsend's were taken in tlie .shelter 

 of the long grass. 



The pond adjacent to the one in which the seals were held and larger in extent 

 did not show any remarkable difference of tempeiature. Both jionds were sheltered 

 among the hills, and the gradual increase of temperature from 50° to 53° may have 

 been due to the effects of the sun as noon was approached. The pond was about half 

 au acre in extent. It is evident from this experiment that Webster Lake, Lake 

 Auton, aud certain of the ponds about Poloviiia could be utilized for liolding the 

 bachelors fi-om these rookeries. The salt lagoon is conveniently located for all the 

 rookeries of the southern end of the islands, and if need be tho.se from Zapadni and 

 Polovina could be driven there. 



At 3 o'clock the seals were driven over and turned into the lagoon. They swam 

 down through the length of the lagoon and crossed over the ueck at the point which 

 is the usual exit of the rejected seals turned out from the killings at Ice House Lake. 



