ON THE ANTIQUE HOUR-LINES. q7 
Some. fragments of ancient dials, are also published by Grx- 
wius *. 
Except the table of Pariapis, the instruments above men- 
_ tioned are each made for an unvarying azimuth. In the de- 
scription of the antiquities of Herculaneum +, there is repre- 
sented and explained a dial whose azimuth is changeable, to 
suit the hour and the different declinations of the sun. It jis 
drawn on an irregularly curved surface of bronze, and the de- 
clinations are marked with the Roman names of the months. 
The ancient names of different kinds of fixed and moveable 
sun-dials, with the names of their inventors, are given by Vi- 
TRUVIUS. 
Something respecting the time of the first introduction of 
gnomonic instruments, is to be collected from Greek and Ro- 
man authors. The ancient inhabitants of Egypt appear to 
have cultivated astronomy at a time prior to the earliest histo- 
rical accounts ; and they have left a monument of their practi- 
cal skill in that science, in the accurate meridional position of 
these most ancient of human works the Pyramids. Portions 
of their knowledge were diffused amongst the Hebrews and 
Babylonians. 
, The astronomical science of the Greeks was derived partly 
from the Egyptians, and partly from the Babylonians {. Tua- 
Es || acquired his knowledge of astronomy and geometry 
from the Egyptian priests, and introduced these sciences into 
Greece. The gnomonic projection of the sphere is a branch 
of the doctrine of spherical astronomy, and when applied to 
the 
* Graevu Thesaurus Antiquitatum Romanarum. 
+ Le Pitture antiche d’Erculano, tom. iii, Napoli 1762. 
+ Heroporvus. > 
}| Diogenes Larrtivs. 
