Andy Dingley wrote:

Don't forget that Ohnes liquified helium in 1911 and discovered
superconductivity almost immediately afterwards. Nitrogen was back in
the 1880's. Now how much technology did any lab have back then that
you can't reproduce in a half-decent modern home workshop ?


This is a fair point, but it would be quite a bit of work none the less.
Got any diagrams etc. of homebuilt kit?


--
Grunff