Volume Six - Pre-Victorian to the Present Day - Select Aspects - Structural Analysis of the river Ely Subway by Rota Design Limited - 2015

Castings could be produced by running the molten iron directly from the furnace into a sand mould, the void being made by a wooden pattern which had obviously been removed. The quality of these early castings was inferior since many inclusions were present and the mix of iron was variable. It became practice to first produce 'pigs' of iron and then remelt and sandcast the necessary component as a second stage.

The quantity of carbon within cast iron is greater than that of steels, typically between 2 - 6% thus the finished cast iron is a brittle material which is weak in tension but had good compressive properties. It suffers a disadvantage over other materials such as wrought iron and early steels in that can't be reshaped by forging or welding, such that a blacksmith might easily undertake with wrought iron.

Allegedly the same building but transformed with cast iron embellishment - it's called 'Mutton dressed up as Lamb' in my book! All the same, a very fine example of 19th century salesmanship from the catalogue of Walter Macfarlane & Company of Glasgow. They made the bandstand for Grange Park, Cardiff (c.1895) and the Louis Samuel Memorial Fountain also in Cardiff of 1908, but which was lost in 1943.