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firs on the best soil was 213 feet, with a diameter of 6½ feet, whilst in Montana it only reached an average height of 148 feet, with a diameter of 2.6 feet, thus showing what an immense influence the soil and rainfall have on the growth of this tree.
From a cross section of Douglas fir grown in Washington and then in the museum at Cooper’s Hill, Dr. Schlich remarks “that the rate of growth indicated in this section, up to thirty years old, resembles that of an average tree in the Taymount plantation in a striking degree, as follows: diameter of average tree at Taymount at 4½ feet, 12 inches; diameter of thirty years’ growth on the section from America, 11.9 inches.
After visiting a second growth area of pure Douglas fir on Ladds farm, about four miles from Portland, Oregon, which was believed to be of about fifty years’ growth ; I came to precisely the same conclusion, and though I had not then seen Dr. Schlich’s article, ] wrote in my journal at the time, that the trees in Oregon were very similar in density to those at Taymount, but decidedly cleaner and better grown, and having regard to their greater age and better soil, they might average 100 feet by 4 feet, and I estimated their cubic contents at something like 6000 feet per acre.
When I first visited Taymount, in April 1904, I determined to estimate it for myself, without regard to what others had done. I therefore paced an area of 100 yards long by 50 yards wide in what I thought a fair average of the whole planta- tion, and found that there were on it ninety-nine trees of the first size, and fifty trees of the second. I did not reckon a number of other trees, which were so small, crooked, or poor, that they could not have been sold profitably with the better ones ; and, judging from a fallen tree which I was able to measure accurately, which was 55 feet long by 10 inches quarter-girth, equal to 38 cubic feet, came to the conclusion that the total volume of saleable timber at forty-four years after planting, or forty- eight years from the seed, did not much exceed 5000 feet per acre.
Sir Hugh Beevor visited Taymount in the autumn after I was there, and made an estimate in a different way by taking three different areas of ¼ acre each, and measuring everything on those areas. He found 96 trees of 12 inches quarter-girth and upwards at six feet from ground; 44 of 10 and 11 inches; 44 of below 10 inches ; and estimated the total contents per acre at 6226 cubic feet.
I revisited Taymount in September 1906 in order to compare it again with what I had seen since in America and in England. I measured twenty trees in the fifth row and twenty in the tenth row from the bank on the east side of the plantation nearest to the high road. I found that their average girth over bark at 5 feet was slightly under 4 feet, the largest being 7 feet 10 inches and the smallest 2 feet 3 inches, I estimated the average timber length of these trees at 60 feet, and the quarter-girth, under bark at half this length, at 8 inches. If this is approximately correct, their average contents would be 26 feet 8 inches, and their total per acre something like 5400 feet, which very closely agrees with my previous estimate, allowing for the increase of two years.
A very different estimate was made by Dr. Somerville in a paper on “Exotic Conifers in Britain,” which was printed in the Journal of the Board of Agricul-