Crookes & Slater, spring-knife manufacturer, was listed in 1856 in Eyre Street.  The partners were Henry Crookes, John Crookes, and John Slater (born c. 1826).  Henry and John Crookes were brothers, living in 1851 with their father, John, in Rockingham Street (all spring-knife cutlers).  Crookes & Slater continued into the early 1860s, making pen, pocket, and sportsman’s knives and Bowies in Eyre Street.  In 1865, Crookes Brothers was listed at 107 Eyre Street – the address of Butler’s Trinity Works (presumably Henry and John rented space in the factory).   In 1868, the firm advertised fine pocket cutlery and Bowies for ‘home, Continental and American markets’.   John, whose first wife (Sarah) died in 1868, apparently died at Randall Street on 11 December 1874, aged 52 (leaving under £1,500).  He was buried in the General Cemetery.  Henry Crookes continued the business.  In 1881, it employed 20 men and six boys.    Henry died on 10 March 1893, aged 63, at Francis Place, Kearsley Road, Highfield.  His obituary noted that he was the sole surviving partner of Crookes Brothers.  His burial was in the General Cemetery.  He left £3,301.