Ya zuwa shekarar 1920 dai, an samu kafuwar kamfanoni fiye da 200 da suke ƙera firinji iri daban-daban a wannan duniya, bisa dogaro da fasahar Injiniya Linden, wanda aka yi ittifaƙin cewar shi ne ya fara ƙirkirar firinji har 'yan baya suka runguma.