In a dispatch from London in 1915:

Then we came to Pimm’s, where good feeds are to be obtained, lobsters and real turtle soup . Did you ever have a Pimm’s No. 1 on a hot day? If not, you don’t know the most glorious drink in London—never mind what it costs, it’s worth it.

You absorb it through a couple of straws, and it runs through cool and refreshing, while the ice clinks musically against the side of the silver tankard, and the green stuff floats about on top, and you see things more clearly through the glass bottom as you regretfully near the end. The only trouble is that once you take the first sip you don’t wish to stop till it’s all gone, and then you want another; but you must not have many “another”; you can find out why for yourself.

– W.A.J. Loveday, London in War Time

Cocktail presentations sometimes change over time but it seems that a Pimm’s Cup still looks about the same as it would a century ago. Side note: after a bit of reading I noticed that references to Pimm’s No. 1 did not start entering American cocktail literature until the 1940’s and 50’s – I wonder if it was strictly a local specialty that was brought back after WW2, or perhaps the popularity increase across the pond was the result of a good marketing campaign by whoever owned the brand during the time?