Edward Dwelly (1864-1939) was an Englishman who, through his service as an Army piper and then work for the Ordnance Survey, became interested in Scottish Gaelic. However, just learning the language wasn't enough for Mr Dwelly. He produced what is still one of the best and most comprehensive dictionaries of the Gaelic language.
Originally, Dwelly's dictionary was only meant for his private use, but when other Gaelic learners found out about it, they encouraged him to make it available to the public. So he set about preparing it for publication, a task that proved a considerable strain on his finances and eyesight. At one point, around page 600 to be precise, he wasn't sure if he'd be able to finish it at all but luckily, a very timely award of Civil List Pension made it possible for him to devote all his time to his dictionary.
The first edition was published in thirty-three parts between 1902 and 1911. It had a Gaelic title, Faclair Gàidhlig le dealbhan ('Gaelic Dictionary with pictures'), and gave the editor's name as 'Ewen MacDonald'. Whatever reasons caused Edward Dwelly to use a pseudonym were removed by the time he prepared the second edition. It was published in 1920 under his own name and in just one volume, which has been its shape ever since. The twentieth century alone saw eleven editions. The 1977 and two following ones use a cover designed by Alasdair Gray; it shows a portrait of the editor together with eighteen trees representing the letters of the Gaelic alphabet. In 1991, the Appendix to Dwelly's Gaelic-English Dictionary (ed. Douglas Clyne) was also published. It contains additional material that didn't appear in print during Edward Dwelly's lifetime.
The remarkable thing about Dwelly's Dictionary is not just the fact that he compiled it completely on his own but also the fact that although his work was based on an earlier dictionary (1831 Dictionary of the Gaelic Language by Norman MacLeod and Daniel Dewar), he expanded it enormously using words from numerous printed sources and over twenty correspondents in different parts of Scotland. Also, the use of illustrations to explain some words, especially technical terms, was a new, and brilliant, idea.
Finally, it's pretty amazing that after so many years, it's still used and still regarded as one of the best. More recent dictionaries are useful enough, but when it comes to less common words, or dialectal variants, or technical terms connected with agriculture, fishing etc., Dwelly's Dictionary is still without equal. Therefore, every Gaelic language enthusiast has a copy. A really sad one has two: one for everyday use and the other just to look at and cherish.
Sources:
Dwelly, Edward The Illustrated Gaelic-English Dictionary 11th edition (Glasgow, 1994).
Thomson, Derick S. (ed.) The Companion to Gaelic Scotland (Glasgow, 1994).