NEW DOSAGE TABLES 9 



40, but it seemed best to adhere- strictly to the round numbers since 

 it introduced no large error. In the size column, 35 and 40 are about 

 0.4 too high, and 16 and 44, 0.3 or 0.4 too low, but all the other num- 

 bers are within 0.2 of the theoretical value. 



Use of the Tables 



These tables are printed in large type so as to be easily read at 

 night. 



All combinations receiving the same dose are on the same line 

 and cannot therefore be confused. 



The important dimension (the distance over the top), is given 

 foot by foot, making it possible to read the dose accurately and rapidly. 

 After a little practice one can read the dose from the large figures 

 only and will be inclined to disregard the smaller type. The rule 

 is as follows where the two dimensions differ : For adjacent dimensions 

 the dose is opposite the lower number, otherwise it is opposite the one 

 just above, unless the difference is six or more lines, that is, where the 

 dose opposite the upper number is more than twice that of the lower 

 in which case look on the second line above lower size. 



The tables can be designated by the upper numbers, thus a 50-20 

 table means that a tree 50 x 50 receives a 20 oz. dose. 



If the tents show .25% leakage and it is decided to use the 50-18 

 table the tent may become tighter after the dew falls and read .20% 

 leakage when it will be safe to use 50-16 table, but on the other hand 

 if a dry wind increases the leakage to .30% by all means change to the 

 50-20 table, or if it becomes .35% take the 50-24 table. 



It will be observed that all these new tables are identical except 

 the shifting of the dose column. 



Relation to Other Tables 



Because of the errors in calculation in the common tables, pointed 

 out in the first part of this bulletin, they are not strictly comparable 

 with chese here presented. In the majority of the doses the table called 

 110% in Circular 129 corresponds closely with a 50-32 table, the 100% 

 with 50-28, 90% with 50-24 and the 75% with 50-20; the last, however, 

 gives some doses as low as in the 50-16 table and equally large errors 

 occur in all. 



