76 



THE POPULAR EDUCATOR. 



be under the same meridian, and, from the reckoning of navi- 

 gators, he found the distance between them to be 5,000 stadia. 

 Now, seven degrees and a half being the forty-eighth part of a 

 great circle of the sphere, this gives the circumference of the 

 earth equal to 240,000 stadia. This was a nearer approximation 

 to the truth than that of Eratosthenes, but it was founded on 

 erroneous data ; for the arc of the great circle between the two 

 places above mentioned was only about 5 15', and tho differ- 

 ence between their two meridians was rather more than 2 



Strabo, who flourished under the reign of Augustus Caesar, 

 corrected many errors of the geographers who preceded him, 

 and made some of his own. The limits of his knowledge of 

 the world were, on the north, lerne or Ireland, and the mouth 

 of the Elbe. He denied the existence of Thule, and asserted 

 that the earth was not habitable at the distance of 4,000 

 ; tadia north of Britain. On the east, he considered Ceylon, or 

 Taprobane and Thinse, the borders of the world, and it is 

 doubtful whether his knowledge of it extended as far as the 

 mouths of the Ganges. He knew the western coast of Africa 



minds of men for a period of no less than twelve centuries of 

 the history of the world. 



When we consider the advanced state of the arts and sciences 

 in the age of Augustus Caesar, at least compared with those 

 which preceded it, we cannot but wonder at the imperfect state 

 of geographical knowledge which existed in the Roman world at 

 this period. Horace considered Great Britain and the Thames 

 as the confines of the earth ; and Virgil, as we have already 

 remarked, placed the source of the Nile in India. The geo- 

 graphical productions of Dionysius Periegetes and of Pomponius 

 Mela, written within a period of fifty years after the Christian 

 era, contain nothing worthy of notice, being mere compilations 

 of what was then known, and by no means improved. 



When the legions of the Emperor Claudius Caesar, A.D. 40, 

 marched to the conquest of Britain, this country was a new 

 world to the Romans. The fleet of Agricola, thirty-five years 

 afterwards, circumnavigated Scotland, explored the surrounding 

 seas, and re-discovered the famous Thule. But even at this 

 epoch Great Britain was still a mysterious country; Tacitus 



ANCIENT EASTERN TRADING CARAVAN ON THE MARCH. 



as far as Cape Nun. But he partook of the error of those who 

 represented the Caspian Sea as united to the Northern Ocean ; 

 and he rejected the positive information of Herodotus on this 

 point. He acknowledged little regard for the authority of this 

 ancient historian, and his doubt on the subject of the voyages 

 of Pytheas, Hanno, and Eudoxus, showed his ignorance of many 

 important geographical questions. 



Strabo adopted the division of the earth into climates 

 recognised by Greek and Roman authors previous to his time. 

 Long before him, indeed, as well as after him, the globe was 

 divided into five zones, namely, two frigid or frozen zones near 

 the poles, one ton-id or central zone scorched by the sun and 

 extending along the equatorial lino on each side of it, and 

 two others called the temperate zones, occupying the rest of 

 the world. The last-named were considered to be the only 

 habitable portions of the globe ; and as to the torrid zone, it 

 was supposed to be condemned, on account of its fiery climate, 

 not only to eternal solitude, but to present an invincible obstacle 

 to the exploration of the countries situated beyond the equator. 

 It will afford an illustration of the force of those ideas which 

 prevailed on the subject of the zones of the globe, and on the 

 relative position of the great divisions of the earth, when we 

 reflect on the fact that they maintained their ground in the 



says it was bounded on the east by Germany, on the south by 

 Gaul, and on the west by Spain. As to Ireland, he places it 

 midway between Spain and Great Britain. The interior of 

 Germany became known to the Romans in consequence of their 

 active commerce with certain northern parts of Europe, which 

 arose from the passion of the Roman ladies for succinum or 

 yellow amber. In the east, a discovery of very great importance 

 advanced the progress of navigation and geography. Hippalus. 

 about the middle of the first century, established the fact of 

 the periodicity of the monsoons, or trade-winds, in the Indian 

 Ocean, which from that period has regulated the motions of the 

 western navigators to India and the Asiatic Archipelago. 



On -the south, the expedition of the Consul Suetonius Paulinna 

 into the country of Sejelmissa, on the borders of the Sahara, or 

 Great Desort of Africa, disclosed those parts of the modern 

 Morocco and Algeria which extend southwards, from the southern 

 side of Mount Atlas to the confines of the sun-scorched desert. 

 The campaign of Cornelius Balbus in a neighbouring and parallel 

 region, was accompanied with still more interesting results. 

 The Roman army set out for Tripoli, traversed the desert, 

 penetrated into Fezzan, and advanced even into the country 

 visited by Messrs. Denham and Clappcrton in 1822, that is, to 

 the vicinity of Bornou. Of the scientific information gained b~ 



