observer,—­his materials being drawn up second-hand, like a modern encyclopaedia.  Nor did he evince great judgment in his selection:  he had a great love of the marvellous, and his work was often unintelligible; but it remains a wonderful monument of human industry.  His Natural History treats of everything in the natural world,—­of the heavenly bodies, of the elements, of thunder and lightning, of the winds and seasons, of the changes and phenomena of the earth, of countries and nations, of seas and rivers, of men, animals, birds, fishes, and plants, of minerals and medicines and precious stones, of commerce and the fine arts.  He is full of errors, but his work is among the most valuable productions of antiquity.  Buffon pronounced his Natural History to contain an infinity of knowledge in every department of human occupation, conveyed in a dress ornate and brilliant.  It is a literary rather than a scientific monument, and as such it is wonderful.  In strict scientific value, it is inferior to the works of modern research; but there are few minds, even in these times, who have directed inquiries to such a variety of subjects as are treated in Pliny’s masterpiece.

If we would compare the geographical knowledge of the ancients with that of the moderns, we confess to the immeasurable inferiority of the ancients.

Eratosthenes, though more properly an astronomer, and the most distinguished among the ancients, was also a considerable writer on geography, indeed, the first who treated the subject systematically, although none of his writings have reached us.  The improvements he pointed out were applied by Ptolemy himself.  His work was a presentation of the geographical knowledge known in his day, so far as geography is the science of determining the position of places on the earth’s surface.  When Eratosthenes began his labors, in the third century before Christ, it was known that the surface of the earth was spherical; he established parallels of latitude and longitude, and attempted the difficult undertaking of measuring the circumference of the globe by the actual measurement of a segment of one of its great circles.

Hipparchus (beginning of second century before Christ) introduced into geography a great improvement; namely, the relative situation of places, by the same process that he determined the positions of the heavenly bodies.  He also pointed out how longitude might be determined by observing the eclipses of the sun and moon.  This led to the construction of maps; but none have reached us except those that were used to illustrate the geography of Ptolemy.  Hipparchus was the first who raised geography to the rank of a science.  He starved himself to death, being tired of life.

Posidonius, who was nearly a century later, determined the arc of a meridian between Rhodes and Alexandria to be a forty-eighth part of the whole circumference,—­an enormous calculation, yet a remarkable one in the infancy of astronomical science.  His writings on history and geography are preserved only in quotations by Cicero, Strabo, and others.