132°, . NEW YORK.STATE MUSEUM 
pears had. begun to open. This insecticide was applied to the 
following trees: 15-28, 34-47, 60-74, 79-91, and 101-14, or in 
other words, to the western end of our experimental orchard, 
a map of which was published in our report for 1900. ;The 
general character of the trees and their varieties. have been pre- 
viously published. and can be ascertained by referring to the 
above report. Tests of the mechanical dilution were made 
while the work was in progress with the following results... At 
tree 19, 54 oil was delivered; at tree 87, a little over 12.3%; at 
tree 108, 144%; at tree 104, 12.54; and at tree 35, 21.5%. Tree 83 
was resprayed, because very little oil was delivered with. the 
apparatus at the first attempt on account of the petroleum being 
low in the reservoir. The above figures vary much more widely — 
than those of. any tests previously made with this apparatus, ~ 
and their divergence may have been due to the pump being 
somewhat out of order, though the precise trouble was not 
located. 
The next day it began to rain about 10 a.m. and ceased about 
noon, beginning again at 1 p. m., and poured from about 1.30 to 
2 p.m., but it did not cease raining till 3 p.m. On the 9th it 
rained some during the night and drizzled or rained most of the 
time between 8 a. m. and noon. It rained some most of the © 
afternoon and during the night, and on the 10th it rained from 
li a.m to3 p.m., also during the night and on the nights of the 
ith and 12th. The weather bureau records at the Albany station, 
less than 3 miles from the experimental orchard, give the pre- 
cipitation as follows: .01 in. on the 7th; .22 on the 8th, .35 on the 
9th and .20 on the 10th, a total of .78 in. or practically one third 
of the rainfall during the month on the day of and the three 
following the application. 
An examination of the trees sprayed with oil showed that 
they were apparently well covered, and the smell of petroleum 
was very marked in the orchard. The rough bark on some of the 
trees seemed to have absorbed the oil pretty thoroughly, but on 
the smooth bark there was an abundance, as very little or none 
had evaporated. The oil remaining on the trees for so long a 
period with comparatively little evaporation was most favorable 
to injury if such would be produced, and consequently a number 
of the trees were examined closely May 6, with the following 
