text: Two different factors seem to have influenced him : his experience working on logarithmic tables and existing work on calculating machines carried out by Blaise Pascal , and Gottfried Leibniz .
simplified: Three different factors seem to have influenced him : a dislike of untidiness ; his experience working on logarithmic tables ; and existing work on calculating machines carried out by Wilhelm Schickard , Blaise Pascal , and Gottfried Leibniz .