From an undated but late Victorian self-help / etiquette book called Don't: A Manual of Mistakes and Improprieties more or less prevalent in Conduct & Speech (Ward, Lock, London circa 1900). The author is noted as 'Censor' and some of the advice still holds, e.g. behaviour in an art gallery...
DON'T neglect to keep to the right of the walk, otherwise there may be collisions and much confusion.
DON'T brush against people, or elbow people, or in any way show disregard for others.
DON'T fail to apologize if you tread upon or stumble against any one, or if you inconvenience one in any way; be considerate and polite always.
DON'T carry a cane or umbrella in a crowd sticking out horizontally before or behind you. This trick is a very annoying one to the victims of it.
DON'T eat fruit or anything else in the public streets. A gentleman on the promenade, engaged in munching an apple or a pear, presents a more amusing than edifying picture.
DON'T stare at people, or laugh at any peculiarity of manner or dress. Don't point at persons or objects.
DON'T turn and look after people that have passed. DON'T forget to be a gentleman.
DON'T spit on the sidewalk. Go to the curbstone and discharge the saliva into the gutter. Men who eject great streams of tobacco-juice on the sidewalks, or on the floors of public vehicles, ought to be driven out of civilized society.
DON'T smoke in the streets, unless in unfrequented avenues.
DON'T smoke in public vehicles. DON'T smoke in any place where it is likely to be offensive.
Wherever you do indulge in a cigar, don't puff smoke into the face of any one, man or woman.
DON'T obstruct the entrance to theatres, churches or assemblies. DON'T stand before hotels or other places and stare at passers-by. This is a most idle and insolent habit.
DON'T, when visiting a gallery...stand in front of any painting which appears to be attractive...DON'T affect artistic or technical knowledge. If you really posses it, DON'T obtrude it.