The Collaborative International Dictionary of English v.0.48:

Solemness \Sol"em*ness\, n.
   Solemnness.
   [1913 Webster]

         Some think he wanted solemnes.           --Sir H.
                                                  Wotton.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Solemnness \Sol"emn*ness\, n.
   The state or quality of being solemn; solemnity;
   impressiveness; gravity; as, the solemnness of public
   worship. [Written also solemness.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

solemness
    n 1: a trait of dignified seriousness [syn: sedateness,
         staidness, solemnity, solemness]