on returning to denmark, he published "de berømte broncedøre for hovedindgangen til baptisteriet i florens, udførte af lorenzo ghiberti" (1862) about lorenzo ghiberti's bronze doors in the baptistry of florence cathedral. he assisted the literary critic clemens petersen and also befriended the norwegian author bjørnstjerne bjørnson for a while, leading in 1870 to a collection of articles he published as "konst og æsthetik" (art and esthetics). in 1872, he wrote a biography of the painter christoffer wilhelm eckersberg titled "maleren eckersbergs levned og værker".