132 NEW YORK STATE MUSEUM v 



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, 5$ oil was delivered; at tree 87, a little over 12.3$; at 

 tree 108, 14$; at tree 104, 12.5$; 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 

 11 a. in to 3 p. m., also during the night and on the nights of the 

 11th 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 



