Complex sentence: Waghorn's route reduced the journey from 16,000 miles, via the Cape of Good Hope, to 6,000 miles: from three months to between 35 and 45 days.
Split into simpler sentences: Waghorn's route reduced the journey from 16,000 miles, via the Cape of Good Hope, to 6,000 miles. In time, that was from three months to between 35 and 45 days.