Mica capacitor type B-517-B no. 469448 by Muirhead and Co. Ltd., March 1969 Mica capacitor type B-517-B no. 469448 by Muirhead and Co. Ltd. 1969
Laminae of white mica, muscovite, "abraki talk mice", Indian, 1851-1930 Laminae of white mica 1851-1930