While I was reading about the major river systems of the world I came upon a very interesting fact: Amazon and Congo once used to be part of the same river system which used to flow west into the modern day Pacific Ocean. See the Wikipedia text:
The Amazon once flowed west as part of a proto-Amazon-Congo river system, from the interior of present day Africa when the continents were joined as western Gondwana. Fifteen million years ago, the Andes were formed by the collision of the South American plate with the Nazca plate. The rise of the Andes and the linkage of the Brazilian and Guyana bedrock shields, blocked the river and caused the Amazon to become a vast inland sea. Gradually this inland sea became a massive swampy, freshwater lake and the marine inhabitants adapted to life in freshwater. For example, over 20 species of stingray, most closely related to those found in the Pacific Ocean, can be found today in the freshwaters of the Amazon.
Ten to eleven million years ago, waters worked through the sandstone from the west and the Amazon began to flow eastward, leading to the emergence of the Amazon rainforest. During Ice Ages, sea levels dropped and the great Amazon lake rapidly drained and became a river, which would eventually become the world’s largest, draining the most extensive expanse of rainforest on the planet
The Amazon travels a total distance of 6,992 kilometers (three times that of the Ganga) discharging about 2,09,000 cubic meters of water per second. It is the world’s largest river by volume and also the world’s second longest river. The Congo travels a total distance of 4,700 kilometers discharging about 41,000 cubic meters of water per second. It is the world’s second largest river by volume and also the world’s deepest river with measured depths of about 220 meters.
Now add up the two and imagine. It will make for a river which will be incredibly huge. Nothing in the modern world would even come close. I am reminded of a Douglas Adams quote here from ‘The Hitchhiker’s Guide to the Galaxy’. “Space” it says, “is big. Really big. You just won’t believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space“. So would have been this river. Really big.