Last-mile delivery a hurdle for drones

WE MAY never see a wholly white Christmas again, if Amazon and Google had their way. Instead, by this time next year, the treetops may be speckled by black little drones flying overhead to deliver gifts on Christmas morning.

The two tech giants are placing big bets on developing a system of drones to deliver goods. Amazon revealed with some fanfare its experiment with a delivery-by-drone service, named Amazon Prime Air, in which small drones would ship goods from an Amazon fulfilment centre directly to customers.

Google, not to be outdone, recently said that a five-foot (1.5 metre) single-wing prototype from its Project Wing carried supplies including candy treats, cattle vaccines, water and radios to two farme…