804 ROYAL SOCIETY OF CANADA 



grapliical miles. Tn slaiute miles it is variously calculated from 24,874 

 to 2r),(i2() miles, for, as the earth is not a perfect sphere, these measure- 

 ments are only close ïipj^roximatione. For the same reason, the length 

 ot a degree on the equator is estimates at from G9*l to 69*5 statute 

 miles. In current speech the latter measure is sometimes given, though 

 the former is more nearly correct. 



All the countries of Western Europe which fell under the intluence 

 of Rome retained permanent traces of the itinerary measures of the 

 Empire in the mile, or mille passuum of the Roman soldier. In the 

 Latin countries the measure persisted ; and even in England, nearly 

 until the end of the reign of Elizabeth, tlie mile was 5000 feet or 1000 

 places ; and was only 146 feet longer than the Roman mile. In the 

 eastern part of the Empire the Greek stadium was the standard and so 

 continued until the Mohammedan invasion. The Roman geographers 

 borrowed tlieir science from the Greeks and used in their writings the 

 Greek sttmdard measure, and this continued to be the measure used 

 by writers on cosmography throughout the middle ages ; for after the 

 time of Ptolemy no original work was done, save by the Arabians, until 

 long after the period now under review. The stade is continually cited 

 in the literature of the age of Cohunbus and it is a very convenient 

 measure, for it bore an accepted and simple ratio to the mile and league 

 of those days. Ptolemy was the chief authority, but the works of 

 Aristotlo, Eratosthenes, Str'abo and other Greeks, as well as the Roman 

 writers, Pliny, Maerobius and Pomponius Mela,, were continually re- 

 ferred to with deference. It is difficult to realize the persistent weight 

 of the authority of Ptolemy. Not until 1569 did Gerard Mercator 

 lead tlie way in revolt and all traces "of the great error of Ptolemy, as 

 to the length of the Mediterranean Sea, did not disappear from the 

 maps until the beginning of the last century. For 1500 years Ptolemy 

 reigned supreme and, therefore, it is not lost labour to study the Greek 

 geographers, if we wish to understand the age of Calumbus. 



The true circumference of the earth was not known to the Greeks, 

 and they made difïerent estimates ; from Aristotle, 400,000 stades, to 

 Ptolemy, 180,000 stades. The estimated length of a degree of the 

 equator varied in proportion, from 1111 \ to 500 stadee respectively. 

 In Appendix E, I have given a comparative table of the length of the 

 c(juator and of a degree thereof as held by the chief geographical writers, 

 from Aristotle down to the date of the convention at Badajoz. The 

 figures are given in Greek stades, and Italian leagues and miles. In a 

 separate column is the translation of these ligures into nautical miles 

 of the present day. The compilation has been made in order to assist 

 the student in grasping quickly the value of these ancient measures. 



