78 ON THE ANTIQUE HOUK-LINES. 



the purpose of shewing the parts of the day, constitutes the 

 Sun-dial, an instrument which may be supposed to have come 

 into use soon after the introduction of astronomy. According 

 to Diogenes Laertius and Pliny, the first gnomonic instru- 

 ment that appeared in Greece was constructed by a disciple of 

 Thales, about the 545th year before the Christian era, and 115 

 years before the death of Pericles. Saumaise * contends, that 

 this instrument was for the use of astronomers only, and that 

 sun-dials did not come into general use in Greece till 200 

 years after, that is, a short time before the age of Alexander. 

 The Romans got their first sun-dial from one of the Greek 

 cities of Sicily f, 260 years before the Christian era ; and for 

 nearly a hundred years after, they possessed no artist acquaint- 

 ed with the principles of the instrument, so as to construct one 

 adjusted to the climate of Rome. 



* Salmasii Plinianae Exercitationes* 

 f PtiNii Hist. Naturalis. 



Explanation 



