As a firm which was owned and managed by three generations of the same family over the period 1896-1975, Ferranti was one of the most innovative and successful British electrical and electronics companies of its era. The family remained committed to a technology-led strategy which was implemented through a highly devolved form of organization, giving departmental managers considerable freedom to develop new ideas. This long-termism was also backed up by an extensive reporting system which evolved over the period after 1896, providing senior management with accurate information on both corporate and departmental performance. The article considers how the family matched the images conjured up by the accounting data with the commitment to engineering innovation, concluding that the latter frequently remained the most important priority in this highly unusual British firm.