Yes, quite right, as taught to me by mother who set much store by etiquette. She told me that it was to prevent the lady's skirt from being splashed with mud by the various charabancs and Edwardian carriages driving past over the cobbles in the rain, which was a bit odd in 1970's South Africa as I never did see a cobbled street or a charabanc or carriage, Edwardian or otherwise, there. Of course, this advice runs counter sometimes to the need to keep one's sword arm free to run through any villain, ruffian, mountebank or cad who would dare steal from or impugn the honour of the good lady on one's arm.
I suspect she got all this stuff from her grandfather, a military man and a disciplinarian, infamous for meeting his daughter, 21 years old of age, in the street and walking up to her and using his pocket handkerchief to publicly wipe the faint hint of lipstick off her mouth with a "I will not see any daughter of mine daubed like a common harlot!"
I guess this is why she insisted on sending me to a boys school that wore boaters and where you could be savagely caned for not doffing your boater to male teachers and removing it completely in the presence of ladies. The boater was much hated by all of us and often used as a frisbee but now missed by me in a nostalgic, whimsical kind of way for the discipline it engendered amongst the savages that boys are at that tender age.
Caco