A city jaunting car, Dublin. Photo taken between 1930 and 1950. City pavement made rubber tires a necessity. Pneumatic tires (introduced on Paris horse cabs in 1904) provided more passenger comfort than solid rubber but they were subject to punctures. The best quality solid rubber tires were formed around a steel wire core but they required a special machine to fit them onto wheels. Cheaper tires were made up of curved pieces of solid rubber that could be separately attached to a wheel. An important advantage was that damaged sections could be removed and replaced without having to discard the whole tire. This picture shows a late innovation -- tires made of uniform, solid rubber knobs. Source: Reproduction rights owned by National Library of Ireland (call no. VAL 26896). Click here to view source.