Exposure Efeci on White Pine Seedlings 165 



four-hour exposure running from 1.30 to 5.30 p. m. The sun 

 was completely obscured all day. There was a low barometer 

 with rain the next day. There was a perceptible easterly air 

 movement. Temperature 56° to 50° F. 



The spring exposures were made April 7, 1914, forenoon and 

 afternoon, the four-hour exposure running from 8.50 to 12.50 

 a. m. The day was cloudy, temperature 40° to 60° F. Wet bulb 

 thermometer 52°, dry bulb 59°, relative humidity 63 per cent at 

 12.30 o'clock. At 5 p. m. the relative humidity had increased to 

 77 per cent with the temperature falling slightly to 56°. 



Series III. Exposure on a Clear Windy Day. — The fall ex- 

 posures were made during the afternoon of November 1, 1913, 

 the four-hour exposure extending from 1.30 to 5.30 p. m. The 

 temperature ranged from 47° to 40° F. There was a 10-mile 

 northwest wind. The strongest rays of the sun were somewhat 

 obscured by a hazy atmosphere in "Indian summer." 



The spring exposures were made on April 9, 1914, forenoon 

 and afternoon, which was a clear day. The four-hour exposure 

 lasted from 11.10 a. m. to 3.10 p. m. There was a steady north- 

 west wind of about 14 miles per hour. Temperature 40° to 33° 

 F. The ground was frozen in the morning. Wet bulb thermom- 

 eter 33°, dry bulb 36°, relative humidity 73 per cent at 12.30 

 o'clock. By 5 p. m. the temperature had risen to 38° and the 

 relative humidity to 91 per cent. 



Transplanting. — The transplant beds are on high ground with 

 northwest slope and a resulting good drainage. The soil is a 

 rather heavy clay loam. The 4 by 25 feet beds were spaded in the 

 spring. The plants were two inches apart in the row, with rows 

 six inches apart. The planting was done with a planting board 

 on April 7 and 9, 1914. On April 8 there was an all-day rain of 

 1.4 inches. The April 9 planting was followed by light rains on 

 April 12 and 16, with a heavy rain on April 20. From April 1 

 to June 28 there was a total rainfall of 11.7 inches. Except for a 

 two weeks' drouth during the last half of May the summer was 

 very favorable for the success of the planted seedlings. The beds 

 received no subsequent cultivation, although they were weeded. 

 The final count was made at the end of July. 



