THE GIRTH-INCREASE OF TREES. III 
No. 14.—ROBINIA PSEUDACACIA. 
esis Girth in 
f|2nd Half} Inches at 
Year, Apr. | May. ee July. | Aug. | Sept. ee S wile =a res $ 
Observation. 
1892 5 | 5 | 10 | 20 | 20 20 40 
1893 5 64-16: 13h 4 oe ie as 50 
1894 5 5 | 10 | 2 | 2 | 16 20 65 
1895 20 | 25 | 85 | 45 | 30 | 45 | 110 
1896. | 10 | 15 | 15 | 30 | 380 40 | 60 
1897 5 64 367 Ss | O16 eS 70 
Es 
Total, | 30 | 55 | 90 | 140 | 195 | 60 | 175 | 395 
P.c. -| 52 | 96 | 15-9 | 24:6 | 342] 10:5 | 307 | 69:3 12 
The most remarkable fact about this stranger from a warmer 
clime is the general distribution over the six months, combined 
with a great excess of energy in the last half of the season. In 
one year the increase for September was no less than “30; its 
percentage for that month, 10°5, is high; and as to August, 
it takes the premier place among the months with 342 per 
cent., and it is the only month with an individual score of half 
an inch. 
I have no other tree of the species to compare it with, but 
another foreigner—a much older tree, however—has a similar but 
even more extreme record. This is Lirtodendron tulipiferum, 
a handsome specimen, nearly seven feet in girth in 1887, when 
its four years’ record closed. I give the monthly proportions for 
the two trees :-— 
ist 
| | Ist Half 2nd Half 
Apr. | May. |June. July. Aug. | Sept. | goason. | Season. 
: | 
Robinia Pseudacacia 52 | 96 15°9 24°6 | 34°2 105 30°7 69°3 
iri 90 
Liriodendron tulipiferum | 2 4 4 34 43 13 10 
i 
