68 REPORT OF THE No. 3 



traverse made of both the north and south sides of the easterly part of White- 

 water Lake. The Ogoki River, between Whitewater and Whiteclay lakes, was 

 traversed, and a survey was also made of Whiteclay Lake. 



From the lower end of Whiteclay Lake to Waboose Falls, on the Ogoki 

 River, a traverse has been made by Clayton Bush, O.L.S., acting for the Ontario 

 Hydro-Electric Power Commission. My survey was carried to the point where 

 it was possible to connect with the survey made by O. L. S. Bush, after which the 

 party was moved down the Ogoki River to Waboose Falls, where O.L.S. Bush 

 had started his traverse. 



From this point a traverse was carried through to Ombabika Station, on the 

 Canadian National Railway, via Ogoki River, Otter Creek, Kapikitongwa River, 

 Summit Lake, Cross Lake and Ombabika River with its various lake expansions. 



The method of conducting the survey was by transit and stadis, checked by 

 triangulation from stadia-measured bases, as described in previous years. Every 

 effort was made to reduce the errors in reading distances to as near an absolute 

 minimum as possible, and the use of a transit with a telescope sufficiently power- 

 ful to permit of observations being taken on polaris at any time of the day made 

 it possible to almost eliminate azimuth errors. 



On account of the manner in which mapping from aerial photographs has 

 developed within recent years, and as it was the intention of the Dominion Air 

 Board to at once photograph the territory through which this survey was to be 

 conducted, it was not considered advisable to go into as great detail as in former 

 years in mapping out the shore line. It was considered that the traversing of 

 numerous islands and of many deep bays and channels could be dispensed with 

 and the details of these features plotted from the aerial photographs when re- 

 quired. The result was that the work was materially speeded up and much 

 more ground was covered than would otherwise have been possible. The plans 

 of the survey as performed give a representation of the main features along the 

 line of traverse that is sufficiently accurate for all present requirements. The 

 survey as a whole was so carried out as to form part of the aerial photographs 

 -covering the territory for a considerable distance on either side of the line of the 

 traverse. 



Posts were planted at intervals of about a mile apart and marked consecu- 

 tively as in previous years. As no attempt was made, however, to systematically 

 survey all the islands in the lakes and rivers traversed, the islands were not 

 numbered and no monuments were planted on them except in a few cases where 

 a regular post was more conveniently planted on an island than on the main 

 shore. 



Levels were taken at all falls and rapids and across portages connecting 

 different waterways when necessary. All elevations were based on Geodetic 

 Survey Bench Mark No. 1035, being a bolt set in the concrete foundation of the 

 Canadian National Railway water- tank at Collins Station. The elevation of 

 this bench mark is 1263.8698 feet, A.S. Levels were not carried over large 

 bodies of water, but on ascertaining the area of a lake, a water gauge was estab- 

 lished, so that if the water level changed before any further levelling was neces- 

 sary, the change in level could be properly allowed for. In long stretches of 

 river, differences in level were estimated. The elevations given on the plans are, 

 therefore, only approximately correct, but they are sufficiently accurate for all 

 practical purposes for some time to come. 



From Collins to Smooth Rock Lake, the traverse was carried along the 

 regular canoe route through a chain of small lakes which were traversed in 

 passing. The shores of these lakes are mostly high and rocky, and the country 



