Being a survey of British Army life in the later part of the Victorian era -- with enough history and looks forward to situate it. Given that in 1850 the army still had officers who had served under Wellington at Waterloo, and other officers led the troops in World War I, that's a far stretch. (Indeed, at one point it goes back to Cromwell's time, since one unit of Cromwell's army had, by a legal fiction, survived the Restoration.)
Goes through all sorts of topics. Regiments, their conflicts and traditions. Officers and gentlemen get two chapters, one on their character as officers, the other as gentlemen -- and the sort of outside income you needed above and beyond buying your commission to be an officer, and the leisurely sort of life you might lead in a fashionable regiment. The lower ranks. Food -- one general complained of the invention of a portable stove on the grounds it would make the men too comfortable. Relationships with women -- young officers were strongly discouraged from marrying (down to a ball where the captains and subalterns were told they could not dance except with married women), and all officers were expected to snag a woman with some money. The lower ranks needed permission to marry, and this was to be granted seldom because there were only a few places for women to do work about the regiment and they would need to support themselves.
Anyone interested in the social history of that army will find it useful book.