§3. The dimensions of the obelisks which have come down to us vary very much. By consulting the list on pages 9-11 it will be seen that at present the height ranges between 2 to 105 feet. As has already been mentioned, the largest obelisks date back to the time when Egypt entered upon, or was already in, its golden age, that having been the time when the Pharaohs could erect monuments worthy of their reign. Before that time, when they served as grave-stones, the obelisks were of a comparatively small size. Still we find some very large specimens under later dynasties, as for instance that of Psametik II. on the Monte Citorio in Rome, which is 71 feet high, while that of the Ptolemies in Philæ, which is only a fragment, measures 33 feet. The Romans also erected large monoliths, Domitian's obelisk on the Piazza Navona in Rome being 54 feet, and that of Hadrian on the Monte Pincio 30 feet high. Constantine the Great erected the large obelisk at Arles in France, measuring 56 feet, which may have possibly been taken out of a French quarry. There must have been some fixed rule for determining the thickness of an obelisk when the length was given. According to a measurement of all the obelisks we may state, that the base was generally 1/9 to 1/11 of {23}the entire length. Thus the New York Obelisk is 7 ft. 9¼ in. by 7 ft. 8¼ in. at the base, which is about 1/9 of the entire length (69½ ft.). The obelisk of Hatasu is of a somewhat different proportion, the thickness at the base being only 1/13 of the total length. The obelisk with the thickest base is that which is still in the quarry at Assuan, the base measuring 11 ft. 1½ in. by 11 ft. 1½ in. That monuments of such height and thickness weigh a great deal is self-evident. Our New York Obelisk would tip an adequate scale at the figure: 448,000 pounds. Eight of the extant obelisks, however, weigh still more, the heaviest being that of Assuan which, if it had ever been erected, would weigh 1,540,000 pounds, having for a second the Lateran Obelisk in Rome with 1,020,000 pounds. §4. The material of which the obelisks are made is the granite of Syene. It was preferred by the Egyptians on account of its wonderful hardness, durability, lack of flaws (the so-called _maladie de granite_), and its reddish color. It is really the amphibole-granite, but is commonly called Syenite from the name of the place where it is found. Although flaws in it are of rare occurrence, they nevertheless sometimes appear in the obelisks. Whenever they were discovered after the block was detached from the native rock, they did not render the stone by any means worthless, as the Luxor Obelisk in Paris has proved. This had a crack in it at the base from the day of its erection in Thebes, which, when pinned by the Egyptians with a wooden plug at that early time, has not since then interfered in the least with the strength or stability of the obelisk.