The full letter with text and images is here.

Even today, there is still a lot of misunderstanding of roller bearings. Preloads are used that are too high and the precision of such bearings is often questioned.Their load bearing capacity is often under-estimated, although almost every car, van and lorry on our roads runs on roller bearings, often with minimal maintenance.

This letter has some useful perspectives on using such bearings, but most usefully, it has four excellent drawings for arrangements using two, three and four sets of roller bearings in precision machine tools, such as lathes. The simple two-bearing mounting will be familiar to owenrs of mini-lathes. the more complex layouts reward a little careful study, especially as to the 'floating' arrangements for dealing with thermal expansion.

Neil