In several places along the Nile, there are what are known as cataracts, where the current is more intense and the river is shallower. These constituted an obstacle to boat traffic. The First Cataract is at Aswan, which is now where the Aswan High Dam is.
Ida Uhse was less than impressed:
“27th of Jan. [...] It was a beautiful day. We have seen temples more magnificent than this one, but all the temples are constructed in the same architectural style. We then went on the Nile to look at the great floodgates that have been used to dam the river. We could not be too impressed with the Cataract, as we were used to seeing the river Ljusnan. Kl. We returned at 6pm.”
Ida Uhse was slightly more impressed by the Second Cataract:
“Wadi Halfa, 7th of Feb. Had a restless night, disturbed by barking dogs. In the morning, at 6.30, the three of us were in a boat with six rowers taking us to the mountain Abusir. We went past part of the Second Cataract, which was very interesting. The boat often had to navigate between stretches of black gravel: the rocks look like they are made of iron but are in fact sandstone covered in iron-rich sediment from the Nile. The rocks at the First Cataract were made of red granite, however.”
On 14 February they are heading down the Nile again, and Ida Uhse observed once more that the First Cataract is nothing compared to the river Ljusnan, but that it nonetheless flows rather fast:
“14th of Feb. Took the train in the morning to the island of Philae to admire the temple once again. We will stay here another 14 days, but it will likely get even warmer, and then we will be glad to have made this excursion twice. We did not get to Philae today, instead we went on a sailboat down the Nile to the Great Cataract, which even at its widest point does not appear more impressive than the river Ljusnan. We did not go through the rapids, as another sailboat had capsized in the spring and a young girl among the travellers had been thrown against the rocks and killed.”