Pale Fire and Lewis Carroll's Sylvie and Bruno books

Bruno Kretschmar is the main character in VN's novel Camera Obscura (1933). In Ada (1969) Van Veen mentions Alice in the Camera Obscura, a book that was given to him on his eighth birthday:

The Past, then, is a constant accumulation of images. It can be easily contemplated and listened to, tested and tasted at random, so that it ceases to mean the orderly alternation of linked events that it does in the large theoretical sense. It is now a generous chaos out of which the genius of total recall, summoned on this summer morning in 1922, can pick anything he pleases: diamonds scattered all over the parquet in 1888; a russet black-hatted beauty at a Parisian bar in 1901; a humid red rose among artificial ones in 1883; the pensive half-smile of a young English governess, in 1880, neatly reclosing her charge’s prepuce after the bedtime treat; a little girl, in 1884, licking the breakfast honey off the badly bitten nails of her spread fingers; the same, at thirty-three, confessing, rather late in the day, that she did not like flowers in vases; the awful pain striking him in the side while two children with a basket of mushrooms looked on in the merrily burning pine forest; and the startled quonk of a Belgian car, which he had overtaken and passed yesterday on a blind bend of the alpine highway. Such images tell us nothing about the texture of time into which they are woven — except, perhaps, in one matter which happens to be hard to settle. Does the coloration of a recollected object (or anything else about its visual effect) differ from date to date? Could I tell by its tint if it comes earlier or later, lower or higher, in the stratigraphy of my past? Is there any mental uranium whose dream-delta decay might be used to measure the age of a recollection? The main difficulty, I hasten to explain, consists in the experimenter not being able to use the same object at different times (say, the Dutch stove with its little blue sailing boats in the nursery of Ardis Manor in 1884 and 1888) because of the two or more impressions borrowing from one another and forming a compound image in the mind; but if different objects are to be chosen (say, the faces of two memorable coachmen: Ben Wright, 1884, and Trofim Fartukov, 1888), it is impossible, insofar as my own research goes, to avoid the intrusion not only of different characteristics but of different emotional circumstances, that do not allow the two objects to be considered essentially equal before, so to speak, their being exposed to the action of Time. I am not sure, that such objects cannot be discovered. In my professional work, in the laboratories of psychology, I have devised myself many a subtle test (one of which, the method of determining female virginity without physical examination, today bears my name). Therefore we can assume that the experiment can be performed — and how tantalizing, then, the discovery of certain exact levels of decreasing saturation or deepening brilliance — so exact that the ‘something’ which I vaguely perceive in the image of a remembered but unidentifiable person, and which assigns it ‘somehow’ to my early boyhood rather than to my adolescence, can be labeled if not with a name, at least with a definite date, e.g., January 1, 1908 (eureka, the ‘e.g.’ worked — he was my father’s former house tutor, who brought me Alice in the Camera Obscura for my eighth birthday). (Part Four)

According to Van, he was born on January 1, 1870; but, if Van’s eighth birthday is January 1, 1908, he was born on January 1, 1900. In VN’s novel The Real Life of Sebastian Knight (1941) Sebastian Knight was born on the thirty-first of December, 1899. Sebastian Knight (who signed his poems with a little black chess-knight drawn in ink) dies in a sanatorium in St Damier. As V. (the narrator in TRLSK, Sebastian's half-brother) points out, damier is French for "chess board:"

Would I never get to Sebastian? Who were those idle idiots who wrote on the wall 'Death to the Jews' or 'Vive le front populaire', or left obscene drawings? Some anonymous artist had begun blacking squares - a chess board, ein Schachbrett, un damier. There was a flash in my brain and the word settled on my tongue: St Damier! (chapter 20)

In Canto Three of his poem John Shade (the poet in Pale Fire) mentions a game of chess with his wife Sybil who says that her knight is pinned:

"What is that funny creaking--do you hear?"
"It is the shutter on the stairs, my dear."

"If you're not sleeping, let's turn on the light.
I hate that wind! Let's play some chess." "All right."

"I'm sure it's not the shutter. There--again."
"It is a tendril fingering the pane."

"What glided down the roof and made that thud?"
"It is old winter tumbling in the mud."

"And now what shall I do? My knight is pinned."

Who rides so late in the night and the wind?
It is the writer's grief. It is the wild
March wind. It is the father with his child. (ll. 653-665)