At £3.50 for every household downloaded only the most well-heeled genealogist will be making much use of the recently released 1921 Census. Never mind in two or three years it will be free, if the government allows us to live that long.
Despite the cost it is possible to dig out some information for free, especially if you are dealing with unusual names and known locations, for example I dug out a great great uncle of 70 who had recently married a 28 year old, and no, his name wasn't Sion White.
More usefully the site has a search facility that allows you to bring up all manner of sociological information without the need to cough up for cash. For example you can search Welsh speakers by any number of criteria - age, sex, birthplace, occupation, current location etc. The search will give you the numbers and even the names.
Here are a few random results:
Wales had 1374 Welsh speakers born in Radnorshire, although only 141 of them were living in the county. At this point we should remember that the Radnorshire of the registration districts did not coincide with the historic county borders. Large chunks were included with Hay and Builth in neighbouring Breconshire, while other parishes were included with Kington in Herefordshire. The Knighton sub-district included many English parishes, all this the result of a deliberate Victorian policy to tame the wild Radnorians by including them with more civilized folk.
Cwmteuddwr was still 25% welsh speaking in 1921, with Rhayader at just under 10% and St Harmon at 7.6% still exhibiting some vestige of the old native tongue. Nearby Llangurig was still 67% welsh speaking at this time and of course Welsh still dominated in the western parishes of Builth hundred.
Most of the Radnorshire born Welsh speakers lived in the coalfield, 517 in Glamorgan, 52 in Monmouthshire - including my Gwystre born grandmother and 286 in Carmarthenshire. This last being a surprisingly high figure perhaps related to the opening of new pits?
Amongst the usual Joneses, Evanses, Davieses and the like, we find familiar local surnames such as Bywater, Bufton, Hamer etc. It's a reminder that the process of language shift in Radnorshire was part and parcel of a general shift occuring in those parts of rural Wales open to the border. Radnorshire wasn't different just further along the line.