Educated at Penzance and Helston Grammar Schools he qualified as an attorney and practised in Penzance and Redruth.  Edmonds joined the Royal Geological Society of Cornwall (February 11th) in 1814, specialising in the study of the sandbanks and submerged forests of Mount’s Bay contributing to the Literary Gazette (London) and to the Edinburgh Philosophical Magazine.  He contributed many papers to the Penzance Natural History and Antiquarian Society which were collected in a single volume entitled ‘The Land's End District: its Antiquities, Natural History, Natural Phenomena, and Scenery’ (1862).  Edmonds made detailed records of a sudden rise and fall in the sea level on July 5th, 1843 and he subsequently researched previous such incidents.  The event he wrote about, however, is now not considered to have been a tsunami.

As well as geology, Edmonds had interests in archaeology and presented papers on the submerged St. Piran’s Church of Perranzabuloe and researched the possibility of Cornish trade with the Phœnicians contributing his findings to a number of periodicals and ‘Proceedings of the Royal Cornwall Geological Society’ and ‘Proceedings of the Royal Institution of Cornwall’.  In addition, an amateur musician, he contributed hymns to a volume of  ‘Hymns for Festivals of the Church’ (1857).