42 CANADIAN FORESTRY ASSOCIATION 



ary to use circular plots, but for more accurate work square plots are preferable, 

 because they are generally laid out more carefully. They may be laid out by either 

 pacing or measuring their sides, and turning the corners with a magnetic compass 

 or a cross-staff head. 



THE ESTIMATION OF FORTY ACRE SQUARES. 



In fairly even aged timber growing on land comparatively easy to travel it is 

 often a good plan to block out forty acre squares here and there and estimate all 

 the timber on each "forty." Each edge of a "forty" is 440 yards long and it is 

 advisable to blaze the boundaries so the estimators will know when they come "to 

 them. For convenience in estimating, the large square is usually divided into 

 sixteen smaller squares of "2\ acres each, and with edges 110 yards long. Starting 

 at any given corner of the " forty," say the south-east, a flag is placed at the centre 

 of the first small square, each edge of which will then be fifty-five yards from the 

 flag and can be easily located by eye measurement or by pacing. The estimator 

 then goes through the timber on the square, records his estimate, returns to his 

 flag, and goes on to the remaining squares in the order indicated by the accompany- 

 ing diagram. 



Having determined the amount of merchantable timber, it is a good plan to 

 prepare on transparent tracing cloth a map showing its location and the character 

 of the growth. Such a map can be laid over the one showing the topographical 

 features of the tract and thus shows at a glance the relations between the two. 

 Furthermore, we may represent on the tracing cloth the extent and location of 

 each year's cutting and thus have a complete record of the work done from the 

 beginning. 



A DOMINION FOREST SURVEY METHOD. 



When it is necessary to get an accurate estimate of the amount of timber on a 

 very large tract of land and also to obtain a clear notion of its topography for 

 mapping purposes, the most satisfactory method is to run parallel strips across it 

 every quarter of a mile. Strips a quarter of a mile apart and four rods wide cover 

 5% of the tract. If only 2% is required they may be placed half a mile apart, 

 or else made only two rods wide. The advantages of the strip method are; (1), 

 It gives data which enable us to show the topography of the region; (2), It enables 

 us to map the distribution of the different forest types; (3), It gives a good average 

 of all the timber on the tract; and (4), When combined with studies in volume it 

 enables us to predict the growth per acre per year in cubic feet, cords, board feet, 

 or any other desired unit of measurement. 



During the last three years this method has been used by the Dominion Forest 

 Survey parties sent out to the Forest Reserves in Manitoba for the purpose of 

 getting accurate information regarding the topography, distribution of forest types ; 

 kind, location, amount and condition of the standing timber; to make studies of 

 the rate at which it is growing; to study the amount and character of the repro- 

 duction ; note the effect of the forests upon stream flow ; devise means for protecting 

 them against fire and timber thieves, and other matters necessary to know if they 

 are to be put under proper management and preserved from absolute destruction. 

 During the past summer I had charge of a party of twelve men collecting informa- 

 tion of this sort in some of the unsurveyed townships along the eastern side of the 

 Riding Mountain Reserve, in north-western Manitoba. This reserve contains 



