|Waltham 1899-174, 11J 1902|
But the interesting thing is how the jewels are laid out. After the basic seven jewels the most efficient layout is for them to be in pairs top and bottom of each staff and put where they will do most to reduce friction and the impact of that friction on the watch. That will be the staffs moving fastest which happily in a watch are also the ones with the most gearing effect.
So with four additional jewels these would normally be set in pairs on the lever pallet and escape wheel or, as favoured by a number of quality English makers, on the escape and seconds wheel. But on this movement the extra jewels are lined up on the top plate, why?
|Cyma 10J for Thos Russell|
This is so that the buyer (or perhaps a seller?) can show off the watch and claim it has 15 jewels!
Others went further, the second movement shown has ten jewels in the presumed hope that no one will notice that the top pivot of the lever pallet, small and hidden under the balance, is not jewelled.