Hi PaulineJ
gosh its hard to find info on the firm!
My grandfather's sister (now deceased) was married to Chetwyn Earle (1902 - 1954) - one of 9 children born of John William Earle and his wife Ada. (Chet)Wyn went in to the business.
I don't have a lot of info on the business or the family but I do know someone who possibly does - and will see what I can find out. It looks like George Bourne was the 'inventor' (with a number of patents) and John was the practical one. John's grandfather was a plane maker from Middlesex whose son John (John William's father) learnt tube making - moving to Birmingham and making his 'fortune'. They appear to have, at one time, become quite wealthy. I assume that the brass tube was used for war work.
My Gt Aunt (1905) had been just a sales girl in a Music shop (called Priestley's). She was a lovely lady. She used to tell me about her trips out with Mrs Earle (Ada), in the Rolls. They used to go to the Lilac Restaurant (at Marshall and Snelgrove's) for tea and the chauffeur would wait patiently outside. They lived in City Road, which was apparently very posh in those times!!
Some of the buildings are still there, on the Icknield loop of the canal.