Erected before the pylon-gates of temples, they are made of granite, and their dimensions are considerable.

The obelisk of Heliopolis (fig.

108) measures sixty-eight feet in the shaft, and the obelisks of Luxor stand seventy-seven and seventy-five and a half feet high, respectively.

The loftiest known is the obelisk of Queen Hatshepsut at Karnak, which rises to a height of 109 feet.

To convey such masses, and to place them in equilibrium, was a sufficiently difficult task, and one is at a loss to understand how the Egyptians succeeded in erecting them with no other appliances than ropes and sacks of sand.