The sub-fonds contains 8 series, Publications (GEC/4/1), Photographs (GEC/4/2), Photograph Albums (GEC/4/3), Microfiche (GEC/4/4), Microfiche Registers and Card Indexes (GEC/4/5), Films (GEC/4/6), Spare Parts Catalogues (GEC/4/7) and Glass Negatives (GEC/4/8). Records include books, journals, bulletins, articles, brochures and leaflets, photographs, photograph albums, negatives, aperture cards and microfilm spools, registers and card indexes, video tapes (VHS cassettes and Betacam) and 16 mm film reels, of corporate films and corporate and research footage, spare parts catalogues, large glass negatives and smaller lantern slides for the period 1849-1996.