You can apply the same kind of process as used in evacuating Figure Three with the mnemonic hand to the twenty cameras of each column of the Table. This hand is modeled after Aretini's harmonic hand and has twenty places as shown, the tip of the index is used for counting the first three and the thumb takes over from four to twenty. Unlike the twelvefold mnemonic hand, where the thumb is placed on the pads of the fingers, in Aretini's harmonic hand, the tip of the thumb goes on the lines at the joints except for the numbers 10, 11, 12 and 13, which are counted on the fingertips and 20 which is on the nail of the middle finger. Thus,
"one" is counted as you touch the tip of the index to the pad of the thumb,  "two" on the middle joint of the thumb,  "three" on the lower joint of the thumb and at "four" the thumb takes over  and touches the line of the joint at the base of the index, you can see the rest clearly in the figure.
 Memorize the letters of  column BCD  in the twenty places of the "harmonic hand" so that you can easily refer to any camera of any column by simply substituting the letters. When this becomes easy,  you can recite the principles and definitions and rules signified by the letters to read any camera,  make propositions and questions and answe the questions with the help of the rules. You can substitute "cognate" and "dissonant" terms and extend the reach of your investigation.
  In this way, you have an impromptu problem solving or investigating tool at your fingertips. It is a problem solving tool if you apply the rules as questions, and a tool for research and investigation if you apply the rules as rules.
(See the quote from Fr. Marçal, under the title "Questions and/or Rules" in  Ars Infusa)
Questions and/or Rules