Summary of types available
1, Bubble Sextant Mk IX (Stores ref. 6B/151) No Clockwork Averager. View.
2, Bubble Sextant Mk IX A (Stores ref. 6B/218) Two minute period. View.
3, Bubble Sextant Mk IX AM (Stores ref. 6B/312) Two minute period. Telescopic Eyepiece. View
4, Bubble Sextant Mk IX B (Stores ref. 6B/289) One or Two minute period. View
5, Bubble Sextant Mk IX BM (Stores ref. 6B/313)
One or Two minute period. Telescopic Eyepiece.View
The Hughes Head Office was bombed during the Blitz but fortunately the Ministry of Supply had already diversified production with at least two other firms experienced in the production of delicate equipment. Samual Smith and Son, later Smiths Industries, for some time H. Hughes and Son's parent company, and Venner, of time clock fame.
Whilst I cannot always identify one make from the other I have noticed some instruments have a "proper" engraved scale with a wax infill, others have a simple printed scale as per car speedos. These latter scales will peel off if they get wet by the way, so be sparing with water if you decide to wash your instrument! I have realised a letter V in brackets (V) after the year indicates an instrument of Venner production. Those from Samual Smith have S.S. & S. engraved below the Kings crown on the left hand side. I have been given some information regarding the placement of serial numbers as a guide to makers.
