3o6 DISCOVERY REPORTS 



fine day) only on 12 could we work all day, and on 6 more for a part of the day, a total 

 of 18 days out of 30; the remaining 12 were useless for work owing to wind, snow or 



fog- 



The Harbour was triangulated by theodolite angles from all the main stations 



(Fig. i), and angles were also taken to the small beacons and all prominent objects.' 



The engine ran well at some times, but not at others, and unfortunately the motorman 



did not seem able to secure any improvement in its action. Consequently there were 



many unnecessary stoppages, which caused me considerable anxiety, as winds rise with 



amazing swiftness to hurricane force, and shelter is very scarce. We spent much time 



out pf sight of the whaling station, and had we been blown out to sea, there would have 



been the greatest difiiculty in returning (see Appendix III). 



The 3^ in. theodolite was very useful, both because of the speed at which one can use 



it and of its handiness in transport. It has a levelUng bubble and screw of great delicacy 



on the vertical arc, thus enabling one to keep the instrument accurately horizontal and 



yet keep the telescope pointing at the object. It can thus be used for solar and stellar 



observations. For position sights in cold weather it was found infinitely preferable to 



use a theodolite rather than a sextant and artificial horizon, both because of the time 



saved in setting up, of working when gloved, and the absence of the fogging, freezing, 



and other drawbacks of the artificial horizon. 



For the other sights also the theodolite was exclusively used. In taking true bearings 



1 This, briefly, was the procedure : 



The Officer in Charge, with two men (motorman and one seaman) erect D, then return to the pier, man 

 the 'Alert' and steam to the vicinity of B (see Fig. i). The assistant and two other men would meanwhile 

 erect A', then A, then S, then B. The 'Alert' sends the pram (one seaman) ashore and all embark and 

 proceed to C. They erect C (' Alert ' lies off^), re-embark and proceed to G, land the assistant and one man 

 (with theodolite, etc.), who partly erects G. The Officer in Charge meanwhile proceeds to H in the ' Alert' 

 and measures a round of angles from that point, twice or more, i.e. he "makes" H, the assistant meanwhile 

 making G, when ready. In making G and H the beacon flags had to be partly erected, so that they could be 

 mutually observed. "Making " at a station means setting up the theodolite and taking a round of angles two 

 or more times from that station. In each case the beacon has to be taken down or moved to allow the theo- 

 dolite to be erected exactly on the site of the beacon. Both at G and H the erection of beacons is then com- 

 pleted. The Officer in Charge returns to G, picks up the assistant, proceeds to C, drops the assistant, 

 anchors near D, and makes D, while the assistant makes C. He then picks up the assistant and proceeds to 

 B\ the assistant makes B, the Oflicer in Charge makes A'^, then A. The assistant joins him and the base is 

 measured four times, usually twice each way, with a calibrated steel tape. A'' was in this case a telegraph pole 

 and therefore needed only a flag. The 'Alert' was then boarded and steamed to the pier. 



The above work occupied two days and fitted in remarkably well. The assistant being naturally somewhat 

 slower in theodolite work, usually gave the Officer in Charge sufficient time to sail to the next main 

 station and back, or nearly so. The sounding marks were put up while proceeding between main stations. 



The triangulation consisted in closing and computing the appropriate sides in the following triangles: 



NSA {NS 1500 ft. base), DAS and DSC, this giving side SC for the inner harbour scale. 



BCS, BCH, GBH, giving GB, which is the long side used for the scale of the outer bay for Busen Fjord. 

 A check is obtained by working also through NSB, etc. 



The triangles and points were then plotted. It was found that in no case did the error, i.e. the diff'erence 

 of the sum of the internal angles from 180°, in any triangle exceed li'. The base was measured four times 

 as usual and the range of difl^erence was only 3 in., although the conditions were not good owing to strong 

 wind and snow; the surface, however, a sheet of fairly firm and flat snow, was excellent. 



