Unique Collection of late 19th-century off-prints put together & the property of Percy Carlyle Gilchrist FRS 1851-1935. Eminent metalurgical chemist and cousin to Sidney Gilchrist Thomas with whom he developed the "Basic" Bessemer Steelmaking Process using phosphoric ore, whilst a chemist at the Blaenavon Ironworks Monmouthshire during the 1870's. The first Bessemer "blow" on this process was made by Bolkow Vaughan & Co Middlesbrough, in April 1879 and became known as the Thomas-Gilchrist process and the product especially in Germany was called "Thomas " steel. Both men amassed large fortunes but Thomas died from consumption in 1885 aged 35. The collection comprises 13 publications all complete but with both boards detached. The index (illustrated) lists these and includes ILLUSTRATED surveys by "ENGINEERING" of Cambria Iron Company, Springfield Iron Works Albany & Rensselaer Iron & Steel Works Bethlehem Iron Co Works etc.