176 Not'ices refpe&ing New Booh, 



little known as the country where, and the perfon by whom. 

 The author, however, has colleAed from the oldeft authors 

 what islo be found on the fubjeft, and examined it with cri- 

 tical accuracy. The earlieft account of inftruments deltined 

 to mark the lapfe of time by the fun's (liadow is to be found 

 in the Bible and in Homer. A fun-dial conftrufted according 

 to the defcription of Vitruvius was found in the year 1741, 

 among the ruins of a villa on theTufculan hill at Rome. A 

 fun-dial of the fame kind is (till to be feen at Athens, ftanding 

 on the fummit of a rock, to the right of an edifice built by 

 Thrafyllus. 



II. Uj'e of fun-dials, and the divifion of the day into hours^ 

 among different antient notions ; gradual imfroveincnt of the 

 art oj conjlrutling and ifng them to the prefcnt period. — 

 The Indians, Siamefc, Tartars, Perfians, Chaldeans, Egyp- 

 tians, and Chiuele divided the day into 60 hours, and each 

 hour into 60 minutes, &c. Thefe people even employed a 

 gnomon for the purpofe of placing their temples according to 

 the principal quarters of the globe. We know from hiftory 

 that the Chinefe made ufe of gnomons 12 or 15 centuries 

 perhaps before the birth of Chriil. The old (reographers, by 

 examining the length of the fliadows of gnomons of equal 

 height, determined the latitude of places, and the obliquity 

 of the ecliptic. Bcrofus brought to Greece from Afia the di- 

 vifion of the day into twelve hours; and the lirft fun-dial. 

 Anaximander, about fix centuries before Chrifi, made an im- 

 provement in fun-dials, as did aifo Anaximenes. Eudoxus, four 

 centuries before Chrifi, conftruAcd a (lill more pcrfeft fun- 

 dial, under the name of ar. chne. Apollonius of Perga, about 

 a centurv before Chrift, invented the pharctra. Patrocles 

 found out \\\&pelehinon, Dionvfiodorus the fun-dial in the form 

 of a cone, Cieanihcs the hemifphere ox fcaph , Parmenio the 

 pro/hipiJ/oruTfif/ia, Theodofius and Andreas the profpanklima. 

 Vitruvius mak^^-s mention of three other fun-dials ; gonarcba^ 

 ens;enato7i, and antihorcum, without del" tibing them or nam- 

 ing the invtntois. The author dcfcribes all thefe fun -dials 

 with as much precifion as the accounts of them remaining will 

 allow, and witf literary and technical accuracv. There were 

 public fun-dials both at Athens and Sparta. Eratofthcnes and 

 Archimedes employed dials very accurately divided for aftro- 

 nomical purpolcs ; and all the cities of Grc'ece ot any confi- 

 deration foon had public inltruments of this kind. Ring-di- 

 als foon began alio to be ufid. A dial of this kind was luf- 

 pendi'd in the hirye flap of I liero; but the Grecian navigators, 

 fur meafuring the ftale of the fun, the time of the day, and 

 the liars above the horizon, employed rather the hodometer 



defcribed 



