Why use a 1913 dictionary? 

   The revelators chose English words with meanings in use during the 1930s.  This 1913 dictionary is beautifully composed and gives time-appropriate definitions better than modern dictionaries can. 

   1913 definitions are usually the same as 1934 definitions.  For greater precision, you can consult dictionaries from years closer to the revelation.  Some libraries have them.  So do some used book suppliers.