Phillip's exposure meter. Bookform actinometer
Phillip's exposure meter. Bookform actinometer, second model, revised. Manufactured by W. H. Phillips and Son, 98 Truro Road, Wood Green, London N.
Phillip's exposure meter. Bookform actinometer, with instructions and boxwood calculator, slide rule form, second model, revised. Manufactured by W. H. Phillips and Son, 98 Truro Road, Wood Green, London N.
Phillip's exposure meter. Bookform actinometer, second model, revised. Manufactured by W. H. Phillips and Son, 98 Truro Road, Wood Green, London N.
Boxwood calculator - slide rule form - for use with a Phillip's exposure meter. Manufactured by W. H. Phillips and Son, 98 Truro Road, Wood Green, London N.