Thread was getting a bit long...
We have six or seven Leeds & Northrup items, they made some fine equipment. Most of ours are Cambridge Instruments or Pye, and probably all of these originated in the same area of Cambridge in the UK where both companies were based. There were a group of companies in the UK who manufactured such equipment, mostly now extinct.
Probably the pinnacle of their manufacturing were the big Torsion Wattmeters, one of which we picked up a while back as part of a pair on ebay. They are truly lovely pieces of kit. One went on ebay last week:
Always strikes me as 'funny' how some items take on a value which is disproportionate to their use, while others always seem to go for pennies, almost! Peter
-- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk