The "To the Reader" verse is the first impression of type in Shakespeares 1623 COMEDIES, HISTORIES and TRAGEDIES. It faces the famous (or infamous) Droeshout engraving.
Look carefully:
T
W
O=2 and I=1, or 21 letters
and A+A= =Pallas AthenA, the Spear-Shaker

      And the line that makes it interesting is the fifth:

      "O,could he but haue drawne his wit"

      The letters that expose the author's name are: