[1] In 1854 he purchased with John Brown and William Bragge the Atlas engineering works in Sheffield, then a modest establishment covering about three acres.
Shortly after the partners took over the works, the adoption of armour for warships in France (1858) led the company to produce iron plates by a new and cheaper process of rolling welding them.
[1] For several years Ellis was occupied in devising appliances for the manufacture of thicker plates to protect ships against guns and projectiles.
[1] In conjunction with William Eaves he introduced the Ellis-Eaves system of induced draught, and he devised a mill for rolling the ribbed boiler-flues of the Purves and other types, and also in connection with the manufacture of Serve tubes.
The capital rose to nearly three millions sterling; about 10,000 men were employed at Ellis's death, and the output exceeded 100,000 tons of steel per annum.
He took little part in the public affairs of Sheffield, but was a magistrate for the West Riding, and was for ten years chairman of the South Yorkshire Coalowners' Association.