11 
the ring of the summer following the time of blazing. If the cut 
is made in summer (June to July), the ring of the particular season 
may still form a partial beginning of a callus, but would be incom- 
plete at the point where the wound destroyed the cambium. If the 
cut is made in August or later the likelihood of any ring formation 
is generally excluded. 
From these considerations, it appears that generally this record is 
accurate to about half a year, but may at times through mistake fail 
by one whole year. In cases where decay has encroached both callus 
and old wood it may be wrong by several years. But even in this lat- 
ter case the reckoning is not so hopeless as would appear, since there 
are usually a number of cuts from different trees. By a careful study 
of the entire cross section the time may usually be approximated to 
within a very few years. Sucha study, however, will require proper 
equipment, time, and preparatory training. 
B. E. Frrnow, 
Chief of Division of Forestry. 
Approved: 
JAMES WILSON, 
Secretary of Agriculture. 
WASHINGTON, D. C., August 18, 1897. 
© 
