Page:Climatic Cycles and Tree-Growth - 1919.djvu/43

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33
COLLECTION OF SECTIONS.

and all doubt seemed to be overcome. Nevertheless, judging by past experience, unchecked counting leaves a doubt wherever the rings are reduced to 0.1 to 0.2 mm. in thickness.

Another disadvantage of this group is that the trees came from very diverse localities, and hence do not represent homogeneous conditions. Therefore, each section in the group will have special mention. The first number in the group, B 11, was cut from a log of Pinus silvestris lying on the woodpile in the yard of the forest school at Sopteland. The tree had been brought in for firewood late in 1912, but was undoubtedly dead at that time, for the outermost ring checked with the Ös group unmistakably as 1911. This view was supported by the decayed bark and moldy trunk. This section was 9 by 14 inches in size and had the center (date 1734) some 3 inches from one end, producing one of the most uniform cases of eccentric growth which I have seen.

Nos. B 12, 13, and 14 cross-identify most satisfactorily with the Ös group. From one to six individual characters or a most convincing sequence of characters were obvious in every decade. Section 12, a foot across, was cut in 1909, and the last complete ring was unmistakably of 1908 by comparison with the previous group. A section was cut for me at the school in Sopteland. The original was marked "No. 1, 1909, Knagenkjelm, Kaupanger," a location on Sogne Fjord, some 80 miles northeast of Bergen. My section shows the bark and very dense, handsome wood with strongly marked rings. Its center is at 1682. No. B 13, center at 1807, is of about the same size and from the same place, and was marked "No. III, 1909." Its outer ring also identified as 1908. A portion of this section also was cut for me.

No. B 14, center 1779, was marked "No. 1, 1909, Lyster Sanatorium," on Sogne Fjord. As in the other two cases, its outer ring was plainly 1908. A thin section was cut for me. Its size was 12 by 14 inches. B 16 was marked "No. 3, 1909," from the same place. This huge section was 28 inches in diameter and 7 inches thick, and its center was about 1724. There was a series of very small rings from 1787 to 1794 and another from 1806 to 1813. I have no section of it and so no cross-identification could be attempted, but the measures of the recent years agree with No. 14 from the same place.

No. B 15, center at 1633, was also measured at the school and no section retained for comparison with the others. It is the only one from its locality. It was marked "No. 1, 1909, Nestaas, Granvin," on Hardanger Fjord. It was cut in October and the first ring was considered to be of that same year. The rings were very clear back to 1680 and in fact to the center, but between the center and 1680 they were very small.