The car moved away from the Senegalese capital Dakar, and after an hour on the difficult dirt roads, the car crossed a path through vast orchards of mango trees. The mango fruits were large, with a golden yellow color and red cheeks enticing to eat.
The father, who was driving the car, said to his children: Of course you will tell me, “Let’s stop so we can taste the mango fruits.” But the children surprised him by refusing, saying in one voice: No no, we have eaten a lot of mango fruits in this country. We don’t want mango. We want to see the wonder!
Fulfilling the promise:
The father had promised them to show them something strange, and he would let them try to discover its secret themselves. If they were unable, he would explain it to them, in exchange for executing one thing he would order them to do. Before the car left the last mango orchards, the children felt the weather change. The air entering the car windows was blowing cold, as if summer had turned into winter. At that time, their father said: Now close your eyes, and do not open them until the car stops!
The Red Lake:
The car stopped, and they opened their eyes. The sight amazed them and made them shout at the same time: Wow! They saw a wide lake, but it was red. The father looked at them with a smile and asked them: Now, who will reveal to me the secret of the lake’s red color?
The small boy stepped forward saying: It is blood, the blood of a large whale that a hunter wounded. The father shook his head, saying: The lake has no whales, not even small fish! The girl said: Perhaps it is red ink that they poured into the lake to make it red and attract tourists with its color.
The mystery:
The father smiled, shaking his head. Instead of responding with words, he took the children to the edge of the lake and made them scoop the water in their hands and look at it. The water was not red, but transparent and colorless. The older brother asked his father to help him a little in solving the mystery!
The father pointed to white piles arranged regularly on the shore away from the water. These white piles were being extracted by male and female workers from the bottom of the lake, and they brought them to the shore in the bellies of small flat boats. The boy thought at first they were white sand, but when he dared and picked up a grain, put it on the tip of his tongue, he discovered it was salt. However, he could not discover the relationship between salt and the lake’s red color!
Solving the mystery:
Finally, the father spoke and said: The lake appears red without any change in the color of its water, and the reason is the salt that settles densely on the shallow bottom of the lake. Because salt is made of crystals, the crystals analyze the sunlight falling on their surfaces and reflect only the red color from it.
Fulfilling the condition of solving the mystery:
The children waited for their father to announce the thing he had conditioned them to execute if they failed to solve the mystery, and that thing was nothing but that their food be limited to one type only, which is mango only and nothing else!