Evening star. [volume] (Washington, D.C.) 1854-1972, 1882-12-21
Rings mo- Guide to a Trees Age.


papers year ago, declared that he did not trust
the concentric rings Of shrub as q record Of It's
age In years. He had put the popular theory to
a test during his Central American exploration,
and had found 1T to err. DR.. A. Child, In the cur
rent Popular Science Monthly" says he never
until then had seen the authority of this age
record disputed, and when he came, some
months later, to cut down four small trees
which he knew were planted in April, 1871, he
resolved to test the matter, and found that,
although they had only twelve years growth in
them. he could count on each from IS to 40 con-
centric rings. II could select twelve more dis
tinct Ones" he says, between which fainter
andnarrower or sub-rings appeared; nine of these
apparently annual rings on one section were
peculiarly distinct, much more so than any Of
the sub-rings; yet Of the remaining it was diff
cult to decide which were annual and which
were not" DR.. Child then proceeds:
Now, to ascertain what relation or connection
there might be between the meteorology OF the
several seasons and the growth made during the
same, selected from my meteorological records
the maximum, minimum and mean temperature
and the rain fall of the six growing months Of
spring and summer of each Of the twelve years
of growth. These extracts have tabulated and
have also appended to each season the thick
ness of the ring formed. as measured on the
Obilque cut previously described. The exam
inatiOn OF this table shows general relation Of
cause and effect between high temperature
and large rain fall and greater growth But it
falls very far short Of proving q general law of
$50 much heat and SO much water during the
growing season. to produce 80 much wood"
For example, compare the years 1875 and 1873.
The temperature OF 1878 for the season is better
than A in excess OF the season of 1875. and the
rain fall only little over four inches less and
yet the growth Of 1875 is seven times what it
was In 1873. This almost unparalleled growth
Of 1S75-that is, as compared with the other
years-cannOt be explained by the above general
law But think the May and June record
OF that year throws light upon it. Wesee there
maximum heat in May Of 90 (higher than
have ever known it In an observation and rec
ord OF twenty-five years. and a mean tenn
perature OF the whole month, also unequaled,
of IL, and this great heat continued through
the month Of June, and no cold spells after the
heat set In sufficient to check the growth.
Then, In connection with this heat, the ground
was well saturated with water when this heated
term began MAY 81 by 1.62 inches of rain on
the 4th. From this on to the 26th Of June Is
inches more Of rain fell SO apportioned over the
time as to keep the ground saturated. This
synchrOnous excess OF heat and water evidently
produced the abnormal growth And PROBABLY,
that these agents, rightly proportioned, opera
while as one or the other is in excess or absent,
the growth is checked and thus has time to
cOndense and harden, and form these sub-rings;
and the more frequent these alterations, the
greater the number Of them.