DEPARTMENT OF LANDS AND FORESTS FOR 1929 85 



tances to as near an absolute minimum as possible, and the use of a transit with a 

 telescope powerful enough to permit of observations being taken on polaris at 

 any hour of the day made it possible to almost eliminate azimuth errors. Fre- 

 quent observations for azimuth were taken and the details of these observations 

 were recorded on the forms supplied by your Department for this purpose. 



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

 been developed during the past few years, and as this method of mapping will be 

 applied to the Albany River and to the territory adjacent to the survey, it was not 

 considered advisable to go into great detail in locating the shore line. The 

 traverse of numerous islands and of many deep bays was dispensed with as the 

 details of these features can be plotted later from the aerial photographs. The 

 plans of the survey which have already been forwarded to your Department give 

 a sufficiently accurate representation of the main physical features for present 

 requirements. 



The whole survey was carried out so as to form part of the ground control 

 necessary for plotting aerial photographs for a considerable distance on either 

 side of the traverse, and particular attention was paid to accurately locating 

 small islands, sharp points and other physical features which it was thought 

 could be easily identified on the photographs. 



Posts were planted at intervals along the shore and marked consecutively 

 as in previous years. Stone mounds were built around these posts, and bearing 

 trees were marked and recorded in the field notes wherever suitable trees were 

 near enough at hand. A large number of posts however have no bearing trees 

 as very often the most suitable place for a post was on a rocky point comparatively 

 bare of timber. On points such as this there is practically no danger of the posts 

 being destroyed by fire. In a very few cases where it was not possible to secure 

 stones for mounds, and where the ground is too low and wet to permic of suitable 

 pits being dug, a large sound green cedar or tamarac tree was squared and marked 

 instead of a post. This was only done in a very few cases and then only when 

 it was considered that the marked tree had a better chance of remaining as a 

 monument than a post unmarked by a stone mound. 



Twelve metal posts were planted at intervals and marked with the same 

 number as the wooden post planted alongside them. Most of these metal posts 

 are located near waterfalls on the river where they can be used as bench-marks. 

 The elevation of every metal post was obtained and marked on the plan. 



The Albany River is one of the largest rivers in Ontario, and the portion 

 surveyed consists of a series of river stretches connecting a number of lake 

 expansions. Between Lake St. Joseph and Fort Hope on Eabamet Lake there 

 are thirteen rapids and falls at which portages are necessary. In many places 

 the river flows with a rapid current, and there are numerous rapids at which 

 there are no portages cut out, and where care is required in navigating par- 

 ticularly with small or loaded canoes. 



Levels were taken on the river as the survey progressed, and the elevations 

 thus obtained are shown on the plan wherever there is a fall of any magnitude. 

 These elevations are approximately correct only, as actual levels were only taken 

 where there is a considerable drop in the river. Al mg many stretches of the 

 river the change in elevation was estimated. It is felt, however, that the eleva- 

 tions obtained in this way are sufficiently accurate for present purposes as the 

 difference in elevation is accurately shown at all points where water power 

 developments will occur in the future. 



There are several points where water powers of considerable magnitude 

 can be developed. At Smooth Stony Portage a little over eighteen miles below 



