In 1899 he was elected a Fellow of the Royal Society, his application citation reading: Geologist in the Geological Survey of England and Wales, and has served on the Staff since 1874.
To aid his researches he has made a special study of recent and fossil seeds (a subject previously much neglected), whereby much light has been thrown on the climate conditions of later Tertiary times, and on the origin of the British flora.
Author of Geological Survey memoirs on 'Geology of the Country around Cromer,' 1882; 'Geology of Holderness,' 1885; 'Pliocene Deposits of Britain,' 1890, and revised Tertiary portion of 'Geology of Isle of Wight,' 2nd ed, 1889.
Also author of many original papers, including 'Dust and Soils' (Geol Mag, 1884); 'Norfolk Amber' (Trans Norf Nat Soc, 1884); 'Origin of Dry Chalk Valleys' (Quart Journ Geol Soc, 1887); 'Geological History of the Recent Flora of Britain' (Ann Botany, 1888); 'Pleistocene Deposits of Sussex Coast' (Quart Journ Geol Soc, 1892); 'Natural History of Isolated Ponds' (Trans Norf Nat Soc, 1892); 'Desert or Steppe Conditions in Britain' (Nat Science, 1893); 'Eocene Deposits of Dorset' (Quart Journ Geol Soc, 1896); 'Report on Relation of Palaeolithic Man to the Glacial Epoch' (Hoxne Excavation) (Brit Assoc, 1896)"[3]From 1899 to 1909, Reid undertook the analysis of archaeobotanical remains from the Roman town of Silchester.
[2] In 1913 he published his book "Submerged Forests" in which he postulated a drowned land bridge between eastern England and the European mainland.