THE CURVE OF THE BIG TREES. 143 



the bottom and high enough so that the men actuallj^ stand within it. In this way they 

 chop 10 feet more or less into the tree, until they approach the center. Then they take a 

 band-saw, 20 feet or more in length, and go around to the other side. For the next few 

 days they pull the great saw back and forth, soaking it liberally in grease to make it slip 

 easily, and driving wedges behind it in order to prevent the weight of the tree from resting 

 on the saw. Finally, when the tree is almost cut through, more wedging is done, and 

 the helpless trunk topples over with a thud and a stupendous cracking of branches that 

 can be heard a mile. The sawn surface exposes the rings of growth so that all one has to 

 do is to measure them, provided the cutting has taken place recently. 



Even in old stumps it is comparatively easy to measure the rings. The sequoia is so 

 wonderfully durable that as soon as one cuts half an inch below the surface of a stump 

 the wood is almost fresh, even though 30 years have elapsed since the tree was cut. This, 

 however, is true only of the heart-wood. The 6 inches of wood on the outside of each 

 trunk, that is, the portion in which sap was actually flowing at the time of cutting, are of 

 quite a different quality. The wood is white instead of deep red like the main body of the 

 trunk, it is soft, and it decays rapidly, so that at the end of 20 to 30 years it is often quite 

 rotten, although enough generally remains to permit the counting of the rings. On the 

 smoothly sawn surface of the stumps the rings are often so clear that one can measure 

 them easily and accurately with no preparation whatever, or else with no preparation except 

 scraping off the pitchy sap which has been exuded from within, or brushing off an accumu- 

 lation of pine needles and dirt with a whisk broom. A little experience, however, soon 

 taught us that while the larger rings could be measured with accuracy, the smaller ones 

 were apt to be missed unless greater precautions were taken. Therefore we made it a 

 practise to chisel grooves an inch or more deep in the more difficult portions of each tree, 

 and in the latter half of our work we chiseled the entire distance except for some of the 

 large rings toward the center. During the first season, except in the case of especially 

 old or difficult specimens, only one measurement was made upon each tree. Our practise 

 was to select the best possible radius, usually the longest and clearest, and always as free 

 as possible from knots. During the second year we invariably measured two radii on each 

 tree, and often three or even four. We also went back to many of the trees done the year 

 before and measured them again along other radii. 



One of our chief difficulties lay in the fact that in bad seasons one side of a tree often 

 fails to lay on any wood, especially in cases where a clump of trees grow together in the 

 sequoias' usual habit, and the inner portions do not have a fair chance. Often we found a 

 difference of 20 to 30 years in radii at right angles to one another; and in one extreme case, 

 one side of a tree 3,000 years old was 500 years older than the other, according to our count. 

 All these tilings necessitated constant care in order that our results might be correct. 

 Another trial lay in the fact that in spite of the extraordinary durability of the wood, a 

 certain number of decayed places are found, especially at the centers of the older trees, 

 exactly the portions which one most desires to see preserved. 



The net result of our work is summed up in the tables on pages 301 to 330. From 

 these it will be seen that we measured a total of 462 trees, 11 of which were entirely dis- 

 carded, because repeated measurements failed to agree, or because of other known sources 

 of error. Among the 451 trees actually used, 108 were measured along only one radius, 

 234 along two radii, 89 along three, 18 along four, and 2 along five. For the most part 

 those measured along only one racUus were young trees in which there was small opportunity 

 for error. A number, however, were old trees located in the valley of the Tulare River which 

 we visited in 1911, but did not return to in 1912. A few others, located in regions which 

 we revisited, could not be found a second time, or else could not be identified because at 

 the beginning of our work we failed to number the stumps, a practise which we followed 

 carefully most of the time. The numbers were chiseled on the flat surface, and are there 



