Ptolemy or optical factors and those caused by judgmental factors. He offered an obscure explanation of the sun or moon illusion (the enlarged apparent size on the horizon) based on the difficulty of looking upwards. There are several characters or items named after Ptolemy, including: [[File:Ptolemaeus - Quadripartitum, 1622 - 4658973.tif|thumb|"Quadripartitum", 1622]] [[Category:Ptolemy| ]] [[Category:100 births]] [[Category:170 deaths]] [[Category:1st-century Romans]] [[Category:2nd-century Romans]] [[Category:2nd-century philosophers]] [[Category:2nd-century poets]] [[Category:Egyptian calendar]] [[Category:Ancient Greek astrologers]] [[Category:Ancient Greek astronomers]] [[Category:Ancient Greek mathematicians]] [[Category:Ancient Greek music theorists]] [[Category:Astrological writers]] [[Category:Claudii]] [[Category:Egyptian astronomers]] [[Category:Egyptian mathematicians]] [[Category:Epigrammatists of the Greek Anthology]] [[Category:2nd-century people of Roman Egypt]] [[Category:Ancient Greek geographers]]
Stone Tower (Ptolemy) Kyrgyzstan; and (iv) the town of Tashkurgan, in Xinjiang, China. However, some historians also consider the Hormeterium, located nearby in the mountains close to the crossover point with China, to be one and the same as the Stone Tower; and believe this landmark to be the settlement of Irkeshtam. All four sites mentioned above, as well as Irkeshtam, can be seen on the "Map of Silk Roads over the Roof of Asia". Stone Tower (Ptolemy) Ptolemy, the Greco-Egyptian geographer of Alexandria, wrote about a "Stone Tower" (λίθινος πύργος in Greek, "Turris Lapidea" in Latin) which marked the mid-point on the