t 



434 Part III. — Seventh Annual Report 



pond. After being well cooled by immersion for half an hour in cold 

 water they proved to be excellent. 



I hope during the present summer to investigate the subject experi- 

 mentally and on the completion of my analysis and experiments to 

 comnmnicate the results in a future report. If the source of heat is purely 

 solar, it seems highly probable, that the system will be found capable 

 of wide application. 



The temperatures observed in the Cattegat and Sound range from 57-55° 

 F., if one observation be excluded, where the bottom temperature was 

 found to be 52° F. at a depth of 20 fathoms. In the Baltic the 

 temperatures observed were lower, ranging from 54°*7 to 50 o, 3 F. Time 

 did not permit of any extensive series of observations during this part of 

 the cruise, but this is the less to be regretted as very full data on the 

 subject has been published for years by the Kiel Commission and the 

 Danish Meteorological Institute. 



I cannot close this brief account of the more immediate results of the 

 cruise of H.M.S. 'Jackal ' without expressing on behalf of those who took 

 part in it our grateful sense of the kindly and hospitable welcome accorded 

 to us on all hands at Bergen, Copenhagen, and Kiel, the three ports at 

 w 7 hich we made stay. It is not too much to hope that such friendly inter- 

 communication between those working with a common object in view on 

 the different shores of the North Sea may lead to a much more rapid 

 solution of the many interesting problems, practical as well as scientific, 

 connected with this important region. 



