The cast iron process of early industrial products lends itself to ornamentation, culminating in designs of the high Victorian period in Britain and its Empire. This paper aims to investigate the geometries employed to create cast iron products, examining samples for industrial and domestic use from the 19th century, in a case study: a vintage treadle sewing machine. By reconstructing the working drawings, the use of gothic geometry such as reticulated tracery design is investigated. The suitability of gothic revival or historicizing ornamentation for the construction with lattice or net patterns is also discussed, questioning an apparent division of industrial design history in a functional and a decorative tradition. The case study employs the following methods: photo documentation, tracing of patterns, measuring, reconstruction of the draughting plan in preparation for the sand casting forms, also, to a lesser extend, contextual research and archival study. This paper will demonstrate how geometric designs such as reticulation - found in the case study - are composed, and these are juxtaposed with gothic window tracery of the English Decorative style by referring to examples in ecclesiastical architecture