Arithmometer by Elliott Brothers, London, no.268, capacity 8x9x16, used by Prudential Assurance Company [B4343, A166775]

The arithmometer was the first mechanical calculator to be developed on a commercial scale. Although technically invented in 1820, its impact was not felt until the 1870s. The Prudential Assurance Company, established in 1848, was an early customer, replacing its human ‘computers’ with these mechanical calculators. We know, however, that its first batch of machines from ??? was not a success and had to be sent to France for repair, so the company then commissioned English machines from Elliot Bros. The Prudential was very innovative in its approach, allowing it to take and maintain the lead in industrial assurance, principally the provision of funeral expenses for the working class.