89 
I do not know whether the breadth of the rings has 
been accurately reproduced and have not made measure- 
ments, therefore. Still Î could not resist the temptation 
of reading off some of the times of conspicuous maxima 
in the growth. 
To my satisfaction — also, [| confess, to my no small 
surprise, Ï find that they lie, nearly all, 12.4 years or 
multiples thereof, apart. 
ÏJ do not mean that each 12!/,th year you will find a 
maximum. Often there will be no well marked maximum. 
But the existing maxima lie multiples of that period apart, 
or very nearly to. Not only that. This period leads 
us, in the 18th and 19th century exactly to the years of 
maximum found for the European trees. 
There may be much in this which is accidental. 
Still, I think, you will not wonder, that I conclude by 
expressing the hope that somebody may be found in your 
country to take up this interesting question, which, per- 
haps nowhere in the world holds out as good a promise 
of success. 
Às the time is still early let me add one last word. 
It seems not probable that we will find trees wholly 
dependent on rain or wholly dependent on temperature 
or, in short, dependent on one single factor. Now in 
one sense this is certainly a great drawback. It would 
be beautiful if we could have some very old tree which 
would be practically a rain-gauge for the last 2000 years 
and another, of another species and perhaps very diffe- 
rently located, which would similarly have taken down 
the average summer temperature during that same inter- 
val and so on. Such an ideal case is too good to be 
believed in. In all cases the growth will certainly depend, 
though in a very different degree, on many, if not all 
the meteorological elements. 
