The Chink in the Armour by Marie Belloc Lowndes

With easy, leisurely steps, constantly stopping to look into the windows of the quaint shops they passed on the way, Sylvia Bailey and Anna Wolsky walked up the steep, the almost mountainous byways and narrow streets which lead to the top of Montmartre.

The whole population seemed to have poured itself out in the open air on this sunny day; even the shopkeepers had brought chairs out of their shops and sat on the pavement, gaily laughing and gossiping together in the eager way Parisians have. As the two foreign ladies, both young, both in their very different fashion good-looking, walked past the sitting groups of neighbours -- men, women, and children would stop talking and stare intently at them, as is also a Parisian way.