194 JOURNAL OF FORESTRY 



operation. An experienced crew of workmen can shift the pan from 

 one bed to another in ten minutes. With the equipment in good work- 

 ing order so that delays do not interfere with the work, it is safe to 

 estimate that one bed can be steamed each hour throughout the day, 

 allowing 45 minutes for actual treatment of each bed. 



RESULTS 



In the spring of 1916 five beds lying in consecutive order were 



selected as experimental beds to determine, as far as possible, the 



amount of steaming required to produce satisfactory results. The 



ground within these five beds had never before been used for growing 



evergreen seedlings and was uniform throughout in physical character 



and fertility, as far as could be determined. Their position in the 



nursery, according to the regular order of numbering the beds, is 



2, 3, 4, 5, and 6. Bed No. 2 was steamed 45 minutes, No. 3, 30 minutes, 



and No. 4, 15 minutes. The seed sown in these beds was covered with 



sterilized sand. Bed No. 5 was not steamed, but the seed was covered 



with sterilized sand, the same as was used in beds 2, 3, and 4. Bed No. 



G was not steamed and the seed was covered with unsterlized sand. 



The detailed record of the treatment of these beds is : 



Bed No. 2 — Steam turjied on at 1.05 p. m., and continued until 



1.55. A pressure of 130 pounds was maintained throughout the 



treatment. 



Temperature at 1.55 at depth of 3" was 97° C, at 8" 94° C. 

 Temperature at 3.25 at depth of 3" was 62° C, at 8" 56° C. 

 Temperature at 5.20 at depth of 3" was 46° C, at 8" 48° C. 



Bed No. 3 — Steam was turned on at 10.57 and continued until 



11.27. The steam gauge showed a pressure of 145 pounds at the 



beginning of the treatment. This pressure fell to 135 pounds at the 



close of the treatment. 



Temperature at 11.27 a. m. at depth of 3" was 98° C, at 8" 98° C. 

 Temperature at 1.05 a. m. at depth of 3" was 60° C, at 8" 68° C. 

 Temperature at 3.05 a. m. at depth of 3" was 51° C, at 8" 44° C. 

 Temperature at 5.25 a. m. at depth of 3" was 48° C, at 8" 40° C. 



Bed No. 4 — Steam was turned on at 10.35 a. m. and continued 

 until 10.50, with a pressure pi 160 pounds at the beginning of the 

 treatment which fell to 130 pounds during the run. 



Temperature at 10.50 a. m. at depth of 3" was 97° C, at 8|| 62° C. 

 Temperature at 1.10 p. m. at depth of 3" was 54° C, at 8" 46° C. 

 Temperature at 3.05 p. m. at depth of 3" was 42° C, at 8" 38° C. 

 Temperature at 5.30 p. m. at depth of 3" was 28° C, at 8" 29° C. 



