20 

 a minute. This division of the curves was found neces- 



sary because of the great height of the ordnant if they 

 were constructed on a scale of .006 of a minute; and if 

 constructed on a scale of 0.02 of a minute, variations 

 from trial to trial would scarcely be noticable. When 

 using the scale of .006 of a minute for later trials 

 it was found feasible to use such denominations as .016 

 of a minute, and .008 of one-half of a minute. 



Having described the construction of the curves, 

 features characteristic of Ourvs I of the latch box can 

 be pointed out. The most important feature is the greater 

 length and irregularity of curves representing the tl 

 and five trials as compared with one trial. This irregu- 

 larity is seen especially in the early trials and is due 

 to the fact that a few more trials are required before 

 the rapid descent in the curve takes place. When one 

 trial a day is given, this descent occurs in the eighth 

 trial and with three and five trials a day, in about the 

 eleventh trial. Already in the early trials there is an 



