149 



filled up ; also, comparisons of temperatures shown by a black-bulb 

 thermometer in the sun's rays, and by others suspended against black 

 and white surfaces, with those of a thermometer in the shade, were 

 frequently made during two years. 



Dr. Joseph Hooker having suggested that some observations should 

 be made on the temperature of the soil at different depths, such were 

 registered at short intervals throughout the winter and spring of 

 1858-59. 



Observations upon the amount of ozone present in the atmosphere 

 were made during the winter and spring of 1857-58, and also for 

 eleven months at Port Kennedy, 1858-59. 



Whenever opportunity offered, the polariscope, supplied at the 

 instance of Professor Stokes, was applied to halos, &c., and the amount 

 and plane of polarization noticed. 



The direction of the Aurora and its influence on an electroscope, 

 together with the periods of maximum and minimum intensity of 

 atmospheric electricity, were observed. 



The periods of maximum and minimum barometric pressure were 

 recorded, as deduced from hourly and two-hourly observations. 



A series of experiments was made on the change produced in sea- 

 water by congelation at different temperatures. 



Deep-sea temperatures and specific gravities were taken when 

 opportunity offered ; also of the surface of the sea constantly. 



The great comet was seen at Port Kennedy, and a few angular 

 measurements taken for determining its change of position, at in- 

 tervals between 13th September and 8th October. 



Selections of native plants, from Port Kennedy and from Disco, 

 have been brought home in Wardian cases, for the Royal Botanic 

 Gardens at Kew. Considerable collections have also been made in 

 the various branches of Natural History ; and Geological specimens 

 from the lands visited have been brought home for scientific friends 

 of the Expedition, who will speedily make public any interesting 

 results : for these collections, and also for many of the observations 

 made during the voyage, I am chiefly indebted to the Surgeon, David 

 Walker, M.D. 



A series of Tidal observations was taken at Port Kennedy ; these 

 will be discussed by the Rev. Professor Haughton, F.R.S., of Trinity 

 College, Dublin. 



