The full title is 'Miscellaneous Papers on Mechanical Subjects - Guns and Steel' and is an important work in the development of military armaments. Whitworth gives an account of his system of rifled guns, showing how it originated and how it has been developed. In the application of this system to large calibre guns he found that in the manufacture of steel by subjecting the metal to extreme pressure when in a fluid state he could produce steel of 'absolute hardness'.