216 THE ARCTIC PRAIRIES 



ground. It had 52 annual rings and 50 or possibly 

 52 whorls of branches. The most vigorous upward 

 growth of the trunk corresponded exactly with the 

 largest growth of wood in the stump. Thus ring No. 

 33 was | inch wide and whorl No. 33 had over 2 feet of 

 growth, below it on the trunk were others which had 

 but 6 inches. 



On the stump most growth was on north-east side; 

 there it was 9 inches, from pith to bark next on east 

 8^ inches, on south 8 inches, north 6J inches, west 6J 

 inches, least on north-west side, 6 inches. The most 

 light in this case came from the north-east. This was 

 in the land of mighty timber. 



On Great Slave River, the higher latitude is offset 

 by lower altitude, and on June 2, 1907, while among 

 the tall white spruce trees I measured one of average 

 size 118 feet high, 11 feet 2 inches in girth a foot from 

 the ground (3 feet 6J inches in diameter), and many 

 black poplars nearly as tall were 9 feet in girth. 



But the stunting effect of the short summer became 

 marked as we went northward. At Fort Smith, June 

 20, I cut down a jackpine that was 12 feet high, 1 

 inch in diameter, with 23 annual rings at the bottom; 

 6 feet up it had 12 rings and 20 whorls. In all it 

 appeared to have 43 whorls, which is puzzling. Of 

 these 20 were in the lower part. This tree grew in 

 dense shade. 



At Fort Resolution we left the Canadian region of 

 large timber and entered the stunted spruce, as noted, 

 and at length on the timber line we saw the final effort 

 of the forests to combat Jack Frost in his own king- 



