This carte de visite is the first portrait that I have found by one of Derby's earliest photographers, John Westmoreland (1820-1895). Arriving in Derby in the late 1840s, he worked for John Davis & Son, a firm of opticians, mathematical & mining instrument makers and photographic equipment suppliers in Irongate. He was primarily employed as an mathematical instrument maker and optician, although Craven (1993) reports that photographs by him from the period 1855-1861 are known.
According to the caption on the reverse of the card mount, the elderly man with the coat and top hat is John Froggatt. I estimate that he is in his 60s or 70s, and that the photograph was taken in the very early 1860s, implying a birth date of the 1780s or 1790s. I haven't yet been able to find out anything about this gentleman, and would appreciate any hints from readers as to who he might be.