Tentamen hydrophytologiae danicae; continens omnia hydrophyta cryptogama Daniae, Holsatiae, Faeroae, Islandiae, Groenlandiae hucusqve cognita, systematice disposita, descripta et iconibus illustrata, adjectis simul speciebus norvegicis. Opus, praemio ab Universitate regia hafniensi ornatum, et sumtu regio editum Q Science
Transits of Venus : a popular account of past and coming transits from the first observed by Horrocks A.D. 1639 to the transit of A.D. 2012. Also an account of the successes achieved in December 1874 and suggestions respecting the transit of 1882 Q Science
