332 DISCOVERY REPORTS 



might be linked up later with the rest of the survey, and in making detailed plans of 

 certain of the harbours themselves. 



Positions were fixed on land by solar observations at Scotia Bay, ChristoiTersen Island, 

 Borge Bay and Sandefjord Bay. With these fixed points all other observations were 

 linked up. All four were fixed by sextant and artificial horizon, two sextants being so 

 employed that each set of observations was in duplicate. 



Three of the more important harbours, those of Borge Bay, Ellefsen and Sande- 

 fjord, were surveyed and sounded. In the absence of triangulation various other means 

 were employed in achieving this end, means which if somewhat unorthodox were 

 amply justified in view of the despatch with which the work had to be carried through. 

 Much was done in the following manner: the ship was moored with both cables hove 

 taut, and upon the fixed point thus provided by her bow bearings and ranges were ob- 

 tained from all important points on the shore. In conjunction with other means this 

 method was employed in all three harbours surveyed. The whalers were mainly used 

 for sounding, but one of them, provided with a boat's compass and a small rangefinder 

 and manned by experienced oarsmen, was occasionally used for actual coastal work in 

 the harbours when other means were impracticable. The distance traversed was de- 

 termined by the length of stroke, which had been carefully calculated over a known dis- 

 tance. This method was employed with good results in surveying the coast of Christof- 

 fersen Island, a small island flanking Ellefsen Harbour in the west, as well as in certain 

 parts of Borge Bay where the ship's motor-boat with yacht log and compass was also 

 employed. The motor-boat, however, had to be run fast and for this reason was less 

 satisfactory than the slower whaler. Ellefsen Harbour was triangulated from a base 740 

 feet in length, measured by using the stadia lines on the level and the levelling stave, 

 while Michelsen Island, the eastern side of Ellefsen Harbour, was walked round with a 

 boat's compass and small rangefinder, a flag on a staff being sent on ahead. Christoffersen 

 Island, being steep and impassable, was surveyed from a whaler in the manner already 

 described. In sounding the harbours the bow was again used as a fixed point from 

 which those working on the whalers, observing frequent horizontal and masthead 

 angles, ran lines to other points on shore indicated by beacons or flags. No tidal 

 observations were made and the soundings accordingly are not reduced. The extent 

 of the rise and fall, however, is such that corrections to soundings of six fathoms or over 

 are for all practical purposes imnecessary. 



While the surveyors were thus employed members of the scientific staff landed on 

 various points of the group, and plants, animals and rocks were gathered from seven 

 widely separated places, the majority hitherto untrodden by collectors. Very little 

 geological work has been done at the South Orkneys since the days of the Scottish 

 expedition, whose observations were largely confined to Laurie Island. To the best of 

 our knowledge the islands to the westward, Fredriksen and Powell Islands with their 

 adjoining rocks and islets, Coronation Island, Signy Island and the Inaccessible Islands, 

 on all of which we were able to land, have never been visited by a geologist, and the 

 only rock specimens known from any of these islands prior to our visit appear to be 



