|1827||Wheatstone move to 20,Conduit Street,Regent St, W.|
|1829||Charles Wheatstone gains 'Symphonium' patent. A concertina like instrument is shown in the final figure, almost as an afterthought!|
|1844||Charles Wheatstone gains 'Improvements to Concertinas' patent.
The concertina is shown much as it is today.|
Wheatstone publish the first known tutor for the English system Instrucción para tocar la Concertina
|1846||'Instruction Book for the Use of Learners of the German Concertina, of Twenty Keys and Ten Keys' by Carlo Minasi published.|
|1847||Wheatstone listed as 'William Wheatstone, Concertina Maker'|
|1848||John Nickolds with his sons and John Crabb leave Wheatstone to set up as concertina makers|
|1850||Jabez Austin founds firm that is to become G.Jones|
|1860||John Crabb starts his business at 3, Spring Street, Clerkenwell.|
|1861||Death of Louis Lachenal.|
Edward Chidley listed as an individual maker at 28 Store Street, Bedford Sq.
|1862||Death of William Wheatstone.|
|1866/8||Wheatstone listed as 'Wheatstone & Co'. Edward Chidley starts producing the concertinas sold by Wheatstone, characterised by their riveted reeds.|
|1870~||Edward Chidley is operating from Wheatstones Conduit St.
premises as an 'Maker and Importer of Harmoniums,concertinas, etc.'.|
Charles & Mary Ann Jeffries and family move to White Lion Passage, Edgware Road.
|1873||Lachenal change from ,'Mrs. Elizabeth Lachenal, Concertina Maker' to 'Lachenal & Co'.|
|1875||Death of Charles Wheatstone.|
|1877~||The Jeffries family move to 102 Praed Street.|
|1878||Lachenal trade mark registered.|
|1884||John Hill Maccann gains patent for his Duet system.|
|1885||Alsepti and Ballinger register patent for the Bowing Valve.|
|1889||Lachenal 'Edeophone' design registered|
|1892~||Jeffries business moves to 23 Praed Street. Charles & Mary Ann and some other family members are already living in the Kilburn area|
|1896||Butterworth gains patent for 'Crane' Duet system.|
|1899||Wheatstone produce first eight sided 'Aeola' design.
Death of Edward Chidley Snr. The firm of Wheatstone passes to his sons Edward and Percy.
|1902||'The aeola, in its present form, was produced by my father in about 1902': K.V.Chidley writing c.1955|
|1905||Wheatstone move to 15, West Street,Charing Cross|
|1906||Death of Charles Jeffries at Willesden. |
Kenneth Chidley joins the family firm.
|1907||'JEDCertina' design registered|
|1910~||'Jeffries Bros.' (Charles, William, George and Thomas) first appears in listings.|
|1919||Death of Mary Ann Jeffries. The Jeffries business splits up shortly afterwards.|
|1924||K.V. Chidley takes over as Production Manager at Wheatstone.|
|1925~||Charles Jeffries Junior is producing concertinas from his home at 12 Aldershot Road, Kilburn. They are stamped 'C.Jeffries' and often have a reversed 'N' in the address stamp.|
|1933||Lachenal close down.|
|1938||Listing for Jeffries Bros. 18, Lincoln Mews,Kilburn NW|
|1941||Death of Edward Chidley Jnr. Some of the Wheatstone shareholding is acquired by Besson & Co.|
|1945/6|| Wheatstone move manufacture to Frederick Close,Stanhope Place.|
Sales premises remain at West St.
|1948||Besson acquired by Boosey & Hawkes.|
|1949||Death of Percy Chidley|
|1951||Wheatstone move manufacture to Ives St,Chelsea|
|1952||International Concertina Association founded.|
|1953||Death of Charles Jeffries Junior.|
|1955||Wheatstone Mayfair model launched.|
|1956~||Wheatstone move all operations to Ives St|
|1959||Wheatstone move all operations to Duncan Terrace,Islington.
Thomas Jeffries operating from Willesden using the name 'Jeffries Bros.'
|1960||Wheatstone Sales finish|
|1961||Boosey & Hawkes move Wheatstone manufacture to a workshop at Sonorous Works, Edgware, the main B & H Factory|
|1963||Matusewich orders start for Wheatstone|
|1964||Death of Kenneth Chidley.|
Death of Thomas Jeffries
|1974||Wheatstone workshop scrapped by Boosey & Hawkes on death of Sid Watkins (December)|
|1975||Wheatstone Company Sold to Steve Dickinson in December|
|1980||Death of Gifford Chidley|
31st Dec: Name changed from C. Wheatstone and Company Limited to Boosey & Hawkes (Concertinas) Ltd
|1981||Death of Henry 'Harry' Crabb.|
|1990||3rd July: Boosey & Hawkes (Concertinas) Ltd company dissolved.|