Joseph Wright’s English Dialect Dictionary (EDD) is a monumental work by any standard. Published in six volumes from 1898–1905, with detailed entries across 4505 double-columned pages, it’s all the more impressive given that its author was largely self-taught and could not read until his mid-teens. (He described himself as ‘an idle man all my life’.)
After studying philology in Germany, Wright began his pioneering work in English dialectology, aiming in the EDD to include ‘the complete vocabulary of dialect words’ in use since 1700. The Oxford Companion to the English Language says ‘nothing of comparable breadth or depth of dialect scholarship has been published in Britain since’.