OK – so we tried these last night and they are a great way to beat the heat!
From William Yeoward’s American Bar book (pg. 111)

CHRIS’S MOJITO
(Chris is the bar tender – Beaufort Bar at the Savoy)

1 oz. fresh lime juice
3/4 oz. simple syrup
12 large mint leaves – crushed
2 oz. Bacardi white rum
soda water to top

Perfect for this heat – and even better in one of  William Yeoward’s spectacular American Bar tumblers!
Enjoy!