Wikipedia says 'precise clocks' which I would guess was quartz clocks on the back of radio synchronization. It was definitely well within the capabilities of the scientists of this period to precisely calibrate against radio wave time delays from London, Australia, etc.
Wikipedia says 'precise clocks' which I would guess was quartz clocks on the back of radio synchronization. It was definitely well within the capabilities of the scientists of this period to precisely calibrate against radio wave time delays from London, Australia, etc.