AND TRANSPIRATION OF TREES 

 TABLE V 



117 



The average level of the forest floor above water line was 3 ft. 2. in. 



Variation and Description of Apparatus 

 As in preHminary experiments, the apparatus used for getting water 

 content was plain and simple. The psychrometer was home-made- 

 constructed from a Dover egg-beater: tin clamps were attached to 

 hold the thermometers firmly in place, and certain unnecessary wires 

 and plates were removed to avoid interference. A spirit-level was in 

 constant use in adjusting the chemical balances and the improvised 

 table on which they rested. The Clements' photometer with Solio 

 strips was again used in light tests The homeopathic vials were re- 

 placed by plain, business-sized envelopes. For drying purposes, the 

 warming oven of the kitchen range in the farm-house proved adequate 

 and satisfactory. For transpiration tests three homeopathic vials, 

 vaseline, medicated cotton, a pint tin cup, and shears were provided. 



Variation and Description of Methods 

 A heavy, well-seasoned, 2-inch plank, 2^^ feet long by 2 ft. wide, 

 was placed, leveled, and permanently fastened on the above mentioned 

 chestnut stump. On this was placed on end and leveled, a small, heavy 

 dry goods box which sheltered the balances. The box was completely 

 covered with a thick, woolen blanket, over which was spread a pliable 

 oil-cloth. These coverings served to protect the scales from air currents 

 during weighing processes. 



The leaves were pulled from the tree, were weighed immediately, 

 and were placed in a series of dated envelopes marked 8B, 8W, 80, 

 9B, 9W 90, etc. The label indicated the hour of the day and the kind 

 of leaf— beech, witchhazel, or oak. After each weighing, psychrometric 

 and photometric readings were taken, and general weather conditions 

 noted. Such readings were made hourly from 8 a.m. to 5 p.m. either 

 weekly or semi-seekly from the first of May to the middle of October. 



