NOTES AND QUERIES. 129 
which is supported by an electrode made of woven strands of 
copper. Similar electrodes are placed between each layer of 
timbers as they are piled up to the desired height. Alternate 
electrodes are then connected to the opposite poles of an alter- 
nating current supply, and the current is allowed to pass. The 
action is said to decompose the solution and set free metallic 
copper in the pores of the wood. Besides the preservative action 
in thus closing the pores, it is said that a certain amount of 
copper sulphate is permanently retained in the pores, giving an 
additional preservative effect.—TZhe Timber News and Sawmill 
LEingineer. 
A “Bic TREE’s” CENTURIES OF LIFE. 
The following is from a paper sent by Mr Fred Sweetland, 
Arizona, September 1906. 
A remarkable recuperative power following an injury was 
found after examination of the Sequoias of the Converse Basin. 
The effects of certain tremendous forest fires occurring centuries 
ago are registered in the trunks of these trees, and the record 
is completely concealed by subsequent healthy growth. Among 
a number of similar cases, the most instructive record of these 
ancient forest fires was observed in a tree of moderate size 
—about 15 feet in diameter, measured at 5 feet from the 
ground. It was 270 feet in height, and 2171 years old. The 
tree when felled had an enormous surface burn on one side, 
30 feet in height, and occupying 18 feet of its circumference; 
this was found to have been due to a fire occurring a.D. 1797. 
The tree, when cut in r1goo, had already occupied itself for 
103 years in its efforts to repair this injury, its method being 
ingrowth of new tissue from the margin of the great black 
wound. When the tree was cut the records of four fires were 
revealed. The history of the tree was as follows :— 
In 271 B.c. it began its existence. In the first year of the 
Christian era it was about 4 feet in diameter above the base. 
In 245 A.D., at 516 years of age, occurred a burning on 
the trunk 3 feet wide. One hundred and five years were 
occupied in covering this wound with new tissue. For 1196 
years no further injuries were registered. 
VOL. XX. PART I. I 
