ASTRONOMICAL AND GEODETIC OBSERVATIONS. 



23 



Magnetic Bearings for Position of Camps and Headlands. 



The numerous magnetic bearings, taken at important positions on land and upon 

 the ice, were made use of for the construction of a chart,^ scale 1 : 1200 000. The 

 chart depends upon the astronomical results just deduced ; by means of these and 

 a critical use of the bearings and sextant angles, the western shore line and that 

 south of Smith Strait were finally laid down. All detail is taken from Dr. Hayes' 

 original track chart (scale 1 : 600 000), to which I have closely adliered, as far as the 

 above material would permit. 



The longitude of Cairn Point, from observed bearings, is as follows : — 



From bearings at Cairn Point, 

 " " " Littleton Island, 



" " " McGary Island, 



By chronometer, 



72° 



50'] 



73 



10 



73 



05 



72 



48 



Adopted longitude 72° 59' 



The longitude of Foggy Camp, from observed bearings, is as follows: 71° 33', 

 from chronometric determination 71° 17' giving the former result the weight 2, the 

 weighted mean becomes 71° 28', which has been adopted. 



The longitude of Camp Hawks from bearings is 73° 24', from chronometric 

 determination 72° 31' giving the former result the weight 2, the weighted mean 

 becomes 73° 06' or 4'' 52" 24", which has been adopted. 



Dr. Hayes reached Cairn Point May 27th, 3i A. M., and Port Foulke May 28th, 

 10 A. M. 



Survey of Smith Strait. 



On the 27th of October, 1860, Mr. Sonnj;ag measured a base line on the ice 

 from the outer point of the third or Starr Island, near Port Foulke, bearing mag- 

 netically S. 4° 20' W. The length of this base, from two measures with a 91 foot 

 line, was 9097 feet, or 2772.9 metres. The position of Cape Isabella and of Cape 

 Patterson, on the coast opposite, were determined from angles measured at the 

 extremities of this base. 



Readings of theodolite : — 



At Third Island : 



Base end, 

 Cape Patterson, 

 Cape Isabella, 



198° 



312 



348 



51' 

 50 

 43 

 44 

 13 

 15 



At opposite end of base : Third Island, 116 30 



30 



Cape Isabella, 92 03 

 (14 



Cape Patterson, 57 12 

 13 



52' 



52*' 



53 



53 



45 





47 





13 





15 





29 



30 



28 



30 



04 



04 



04 



04 



12 





12 





Mean. 



193° 51'. 9 



312 44.8 



348 14.0 



116 29.5 



92 03.8 



57 12.2 



Solving the triangles : 



(Isabella, \° 



} Third Island, 154 

 (Base end, 24 



11'.8 

 22.5 and 

 25.7 



( Cape Patterson, 1° 49'. 8 

 ■^ Third Island, 118 52.9 

 (Base end, 59 17.3 



^ See large chart accompanying this paper. 



