Time Regained VI pp 1-27

p 1-4 | the two ways (in French, with photos; translation to come); also here.
p 7: Chinese porcelain bowl

p 7 | ... Léa dressed as a man... (cross-dressing)

p 8 |... Pascal's gulf.... From a poem titled "Le Gouffre"  ("The Gulf"), the opening lines of Baudelaire:

"Pascal avait son gouffre, avec lui se mouvant.
— Hélas! tout est abîme, — action, désir, rêve,"

"Pascal had his abyss that moved along with him.
— Alas! all is abysmal, — action, desire, dream,"

p 12 | Marienbad: Mariánské Lázně, a spa town in the Czech Republic. Most of its buildings are from its Golden Era in the second half of the 19th century, when celebrities & European rulers came to enjoy the curative carbon dioxide springs.

p 17 | Empress Theodora: (c.497-548 AD), powerful Byzantine empress, wife of Justinian I, said to have been a low-born actress.

p 21 | ...battle of Ulm...: on 16–19 October 1805 was a series of skirmishes that allowed Napoleon I to trap an entire Austrian army under the command of Karl Freiherr Mack von Leiberich with minimal losses and to force its surrender near Ulm in the Electorate of Bavaria  (wiki).  The Battle of Lule Burgas (1912) was here in the First Balkan War. (Sidenote: its emperor was Theodosius I. We see the fictional Theodosius II visit Paris twice during the novel.)

p 23 | La Fille aux yeux d'or (The Girl with the Golden Eyes): 1835 novel by Balzac, part of La Comédie humaine.

p 25 | Joseph Fourier (1768–1830) was a French mathematician and physicist known for initiating the investigation of Fourier series & their applications to problems of heat transfer and vibrations. The Fourier transform and Fourier's law are also named in his honor; also generally credited with discovering the greenhouse effect.

p 25 | Tobolsk is a town in Tyumen Oblast, Russia, located at the confluence of the Tobol and Irtysh Rivers. Founded in 1590, Tobolsk is the second oldest Russian settlement east of the Ural Mountains in Asian Russia, and is a historic capital of the Siberia region. In the early 1900s, it was famous as the administrative center of Grigori Rasputin's home province, and is located close to his birthplace 

p 26 | the Goncourt Brothers produced the Goncourt Journal together from 1850-1870, then by Edmond alone till 1896. It was a candid chronicle of the literary and artistic Parisian world in which they lived. Proust paid the Journal a tribute by including a pastiche* of it in Time Regained. Some say the Journal's obsessive chronicling of the most minute details of its authors' social lives and rendering of them into literary art anticipates Proust's novel.  (wiki) 

* A pastiche is a work of visual art, literature, theatre, or music that imitates the style or character of the work of one or more other artists. Unlike parody, pastiche celebrates, rather than mocks, the work it imitates. (wiki)