692 



DIALLING. 



History, the means, of dividing time with more accuracy. The 

 V 7~"""Y""""' first step was doubtless the astronomical determi- 

 nation of noon ; an invention which Diogenes La- 

 crtius has attributed to Anaximander, the successor 

 of Thales, who erected a gnomon or pyramid, about 

 600 years before the Christian era. This instrument 

 shewed the time of noon, either by the shortest shadow, 

 or by its falling on a meridian line. It is probable that 

 Anaximander received this invention from his master 

 Thales, who may have learned it in Egypt, where he 

 studied. Pliny has given the merit of it to Anaxime- 

 n es. Certainly one or other of these philosophers gave 

 the first sun dial to the Lacedemonians ; and as the 

 progress of discovery is, in general, slow, it may be that 

 all the three may have had some share in the inven- 

 tion. 

 Origin of 6. Herodotus, however, gives a different account of 

 dialling the origin of dialling among the Greeks. According 

 among the to him, they received the Pole, and the Gnomon, and 

 Greeks. t ]-, e t ii v j s i on f the day into 12 parts, from the Babylo- 

 nians ; and this accords very well with what is stated 

 by other ancient writers, namely, that Berosus, a Chal- 

 dean, founded a school at Cos, where he taught the sci- 

 ences cultivated in his own country. Vitruvius attri- 

 butes the construction of a kind of dial to a philosopher 

 of this name ; and it was probably he that taught to the 

 Greeks the construction of sun dials, and the division 

 of the day into 12 parts. Certain circumstances render 

 it probable that this philosopher lived nearly 540 years 

 before Christ, or about the time of Anaximander and 

 Anaximenes. 



7. The manners of the Romans appear to have been 

 but little favourable to the cultivation of the mathema- 

 tical sciences, and accordingly it was late before that 

 nation adopted any thing like a tolerably accurate me- 

 thod of dividing time. Even in the middle of the fifth 

 century, after the building of Rome, the only periods 

 of the day noted, were the rising and setting of the sun, 

 and mid-day ; which last was proclaimed by a herald 

 when he saw the sun from the senate house, between 

 the Rostra and a place named Grcecoslasis. 



Roman I* has been said that the first sun dial known at 



dials. Rome was placed near the temple of Quirinus, by the 



directions of Lucius Papirius Cursor, about the year of 

 the city 460, in order to fulfil a vow made by his fa- 

 ther. However, Pliny, who relates this circumstance, 

 doubts it ; and shortly after states that the first sun dial 

 was set up near the Rostra, about 30 years later, during 

 the first Punic war, by the consul Valerius Messala, 

 who brought it from Catania in Sicily after the taking 

 of that city. This dial, however, measured time imper- 

 fectly, because it was made for a latitude considerably 

 different from that of Rome. Yet it was used for a pe- 

 riod of 99 years ; and at last the consul Martius Philip- 

 pus, about the year of Rome 590, caused another more 

 exact to be constructed, probably by some Greek, for 

 the Roman arms had then penetrated into Greece. The 

 Romans, however, were still without the means of mea- 

 suring time in cloudy weather and during the night, 

 until about a century afterwards, when Scipio Nasica 

 procured a Clepsydra to be constructed, which was 

 perhaps also the work of some Greek ; for Hero and 

 Ctesibius, who lived under the first Ptolemies, were the 

 inventors of this ingenious machine. 



8. Sun dials, or Horologia, are frequently mention- 

 ed m the writings of antiquity. Menander has intro- 

 duced mtooneofhis pieces, a hungry parasite who had 

 watched on a dial the arrival of the shadow at the hour 

 oi a repast ; but in his eagerness, he had begun so early 



as to mistake the light of the moon for that of the sun. H' at01 7- 

 It is related, that a sun dial having been shewn to Epi- T~"*"^ 

 curtis, he exclaimed, "What a fine invention to hinder us 

 from forgetting to dine !" The Greek anthology has 

 preserved a humorous inscription placed on a sun dial, 

 the meaning of which is, that six hours of the day are 

 given for labour, the remaining four say to mortals, live ; 

 these hours being marked on the dial by the Greek let- 

 ters Z, H, 0, I, which may be supposed to form the 

 word ZH0I, live. 



9. Aulius Gellius has preserved, in his Attic Nights, 

 a curious fragment of a comedy of Plautus, in which a 

 parasite exclaims against sun dials in these terms r 



" Ut eum di perdant, primus qui horas reperit, 

 Quique adeo primus statuit hie solarium, 

 Qui mihi comminuit misero arliculatim diem. 

 Nam me puero uterus erat solarium. 

 Multo omnium istorum optimum ac verissimum : 

 Ubi iste monebat esse nisi cum nihil erat : 

 Nuncetiam quod est, non est, nisi soli lubet." 

 Itaque adeo jam oppletum est oppidum solariis, 

 Major populi pars avidi reptant fame." 



" May the gods confound the fellow who first invent- 

 ed hours, and placed the dial here, which doles out the 

 day piecemeal to me, an unhappy wretch ! For when I 

 was a boy, my belly was my dial, and it was by far the 

 best, and truest of them all : I ate whenever it warn- 

 ed me, that is, if any thing could be had ; but now, 

 whatever there may be, it is not, unless forsooth it 

 pleaseth the sun: Indeed, since the town was filled 

 with dials, the greater part of the people crawl about 

 starving with hunger." 



10. Modern dials, in general, indicate the hour by 

 the position of the shadow on a plane ; but there is rea- 

 son to suppose, that some of the ancient dials shewed 

 the hour by the length of the shadow ; and that even 

 the human body was made, in this way, to serve the 

 purpose of a dial. This mode of determining time, 

 however, had the inconvenience of requiring a table of 

 numbers, to shew the length of the shadow at every 

 hour for different times of the year. An ancient ca- 

 lendar has been preserved by Palladius, a writer of the 

 sixth century, which contains a table of this kind, shew- 

 ing the length of the shadow for every hour of the day 

 at the end of each month. 



1 1 . Vitruvius has preserved, in his writings, the only Ancient 

 notices that have come down to our times respecting dials. 

 the different kinds of ancient sun-dials, and their in- 

 ventors. According to him, Berosus the Chaldean was 

 reputed the inventor of the dial called Hemicycle, hol- 

 lowed into a square, and adapted to the climate. Aris- 

 .tarchus of Samos invented the Scapke, or hemisphere, 



as well as the Discus. Again, Eutloxus of Cnidus, or, 

 according to others, Apollonius, contrived the Ara- 

 cuhe, or Aranea : Scopas of Syracuse made the Plin- 

 thium : The Pros-ta Istoroumena was the work of Par- 

 menion ; and the Pros-panclima that of Theodosius 

 and Andreas : Patrocles was the inventor of Pelecinon, 

 or Bipennis : Dionysidorus of the Cone, and Apollonius 

 of the Pharetra. He enumerates the names of other 

 dials, viz. the Gonarcke, the Engoniaton, and the Anti- 

 boreum; and we also learn from him, that there were 

 portable dials (viatoria pensilia), concerning which dif- 

 ferent authors had Written, and the description of which, 

 he says, depends on the Analemma, which he had pre- 

 viously described. 



12. Of these dials, that of Aristarchus probably was Aristar- 

 the most simple . It was a hemisphere cut in a cubic chus ' dl » -1 - 



