268 



APPENDIX 



One way of using the quadrat method in class work is as follows : 

 6 or 8 100-foot steel surveyor's tapes and about the same number of 

 10-foot tapes are provided, the numl)er depending upon the size 

 of the class. When a place for mapping has been selected 4 of the 



Fig. 117.— Various types of porous clay-cup atmometers. 



Fig. 118.— a portable folding quadrat divided into decimeter squares by means 



of cords. 



long tapes are used to lay out a quadrat 100 feet square, steel tent- 

 pins being used to hold the tapes. A fifth tape is now stretched 10 

 feet from one side of the quadrat in such a way as to lay off a 10-foot 

 strip. The short tapes are used to subdivide this strip into 10-foot 

 quadrats. A party of about three students works on each 10-foot 



