While it had been on my mental To Be Read list for years, I kept putting it off. Would the book be that different from earlier English novels about the humorous confusions of marital and family life? After all, there exists a minor tradition of such comic fiction in Britain, starting with two late-Victorian classics, George and Weedon Grossmith’s “The Diary of a Nobody” (1892) and Barry Pain’s “Eliza” (1900). Perhaps the ne plus ultra of this subgenre, though, remains Stella Gibbons’s group portrait of the Starkadder family, “Cold Comfort Farm” (1932), a novel so much more than its matriarch Ada Doom’s immortal catchphrase: “I saw something nasty in the woodshed.”

The Provincial Lady of Delafield’s title is an unnamed upper-middle-class mother of the 6-year-old Vicky and the somewhat older Robin, and the wife of Robert, a rather taciturn land agent — a kind of estate manager — who mostly just falls asleep in the evenings while reading the Times. The Provincial Lady has female literary friends in London, keeps up with the latest fiction, and regularly interacts with the supercilious Lady Boxe, the well-meaning Vicar’s Wife and the repulsively saccharine valetudinarian Mrs. Blenkinsop. Her domestic staff includes a cook, parlor-maid and gardener as well as a hysterical — in all senses — French governess known only as Mademoiselle.

So where’s the humor? It lies in the Provincial Lady’s ironic outlook on life and her diary’s clipped style, which uses the first person singular as sparingly as possible. In a typical entry, she writes about chatting in a hotel lounge with several other mothers: “We all talk about our boys in tones of disparagement, and about one another’s boys with great enthusiasm.”

When asked by one woman what she thinks of Rebecca West’s “Harriet Hume,” the Provincial Lady confesses to not having started the novel, then adds to herself: “Have a depressed feeling that this is going to be another case of [Virginia Woolf’s] ‘Orlando’ about which was perfectly able to talk most intelligently until I read it, and found myself unfortunately unable to understand any of it.”

When the Provincial Lady returns home from an excursion, she is “struck, as so often before, by immense accumulation of domestic disasters that always await one after any absence. Trouble with kitchen range has resulted in no hot water, also Cook says the mutton has gone, and will I speak to the butcher, there being no excuse weather like this. Vicky’s cold, unlike the mutton, hasn’t gone. Mademoiselle says, ‘Ah, cette petite! Elle ne sera peut-etre pas longtemps pour ce bas monde, madame.’ Hope that this is only her Latin way of dramatising the situation.” (The French, by the way, means: “Oh, the little one! She will perhaps not be long for this world, madam!”)

Throughout, Delafield’s semi-autobiographical heroine addresses mental notes to herself, usually designated “Query” or “Memo” and always set off in parentheses. Here’s an example of the first: “(Query … Does not a misplaced optimism exist, common to all mankind, leading on to false conviction that social engagements, if dated sufficiently far ahead, will never really materialise?)” And here’s one for “memo”: “(Mem.: Interesting subject for debate at Women’s Institute, perhaps: That Imagination is incompatible with Inherited Wealth. On second thoughts, though, fear this has a socialistic trend.)”

The Provincial Lady’s chief worries, aside from her children, are the household bills and bank overdrafts. There’s never quite enough money. When a London shop snootily writes asking whether she has “overlooked overdue portion of account,” she mentally replies, “(Far from overlooking it, have actually been kept awake by it at night.)”

At times, it’s hard to tell how seriously one should take the diary entries. After reading aloud several Grimm fairy tales to Vicky and Robin, their mother notes: “Both children take immense interest in story of highly undesirable person who wins fortune, fame, and beautiful Princess by means of lies, violence, and treachery. Feel sure that this must have disastrous effect on both in years to come.”

More disturbingly, the beset diarist regularly confesses to recurrent feelings of inadequacy. In her dealings with Lady Boxe, she invariably comes up with some clever riposte that she never quite delivers. For instance, when this grande dame condescendingly asks after Robert, “I think seriously of replying that he is out receiving the Oath of Allegiance from all the vassals on the estate.” Over time, she imagines various ways of murdering Lady Boxe: “(Unavoidable Query presents itself here: Would a verdict of Justifiable Homicide delivered against their mother affect future careers of children unfavourably?”).

Indeed, the Provincial Lady — outwardly conventional — inwardly lives a rich, imaginative life. When Lady Boxe damns Robert with faint praise as “such a safe, respectable husband for any woman,” his wife will have none of it. “Give her briefly to understand that Robert is in reality a compound of Don Juan, the Marquis de Sade, and Dr. Crippen, but that we do not care to let it be known locally.”

As it happens, there was a man in Delafield’s orbit who fits this description, Anthony Berkeley Cox, who was madly in love with her. Cox is better known as the great mystery novelist Anthony Berkeley, author of “The Poisoned Chocolates Case” (1929) and, under the name Francis Iles, of that psychological suspense masterpiece “Before the Fact” (1932), filmed by Alfred Hitchcock as “Suspicion” (with a softened ending). Delafield and Cox were close, dedicating novels to each other. Whether they were more than friends remains an open question.

But this aspect of the author’s real life never surfaces in “Diary of a Provincial Lady.” In its pages, Delafield’s husband is portrayed with mild affection, as if he were an elderly sheepdog. Still, at one point the Provincial Lady is “moved to exclaim — perhaps rather thoughtlessly — that the most wonderful thing in the world must be to be a childless widow — but this is met by unsympathetic silence from Robert.”

In what is the high point of her year, our heroine escapes alone to the Riviera for a holiday with her literary friend Rose and Rose’s aristocratic cronies. One day, a strapping Viscountess sets out on choppy waters to swim to a distant rock. On impulse, the diarist joins her: “Long before we are half-way there, I know that I shall never reach it, and hope that Robert’s second wife will be kind to the children.” Somehow, she manages to survive.

Delafield’s stand-in never quite shakes her quiet desperation and, like many of us, regularly soothes this affliction with retail therapy: “Feel that life is wholly unendurable, and decide madly to get a new hat.” On another occasion, when feeling old, she has her hair dyed, and it comes out a horrible mahogany color. Her friend Mary — who always looks cool and elegant — comments that “she cannot imagine why anybody should deliberately make themselves look ten years older than they need.” To which the Provincial Lady inwardly responds, “Feel that, if she wishes to discourage further experiments on my part, this observation could scarcely be improved upon.”

As others before me have long recognized, “Diary of a Provincial Lady” — despite its darker nuances — makes for ideal summer reading. Delafield’s light, delicate humor acts like a balm on ruffled spirits, providing a welcome, and often much-needed, respite from our troublous times.