84 WEIGHTS AND MEASURES. SECT. XII. 



pears from computation that K Draconis was not very 

 far from that place about 3000 years ago ; but as- it is 

 only about 2150 years since Eudoxus lived, he must 

 have described an anterior state of the heavens, sup- 

 posed to be the same that was mentioned by Chiron 

 about the time of the siege of Troy. Thus every cir- 

 cumstance concurs in showing that astronomy was cul- 

 tivated in the highest ages of antiquity. 



It is possible that a knowledge of astronomy may lead 

 to the interpretation of hieroglyphical characters. As- 

 tronomical signs are often found on the ancient Egyptian 

 monuments, probably employed by the priests to record 

 dates. The author had occasion to witness an instance 

 of this most interesting application of astronomy, in as- 

 certaining the date of a papyrus, sent from Egypt by Mr. 

 Salt, in the hieroglyphical researches of the late Dr. 

 Thomas Young, whose profound and varied acquire- 

 ments do honor to his country, and to the age in which 

 he lived. The manuscript was found in a mummy case ; 

 it proved to be a horoscope of the age of Ptolemy, and 

 its date was determined from the configuration of the 

 heavens at the time of its construction. 



The form of the earth furnishes a standard of weights 

 and measures for the ordinary purposes of life, as well 

 as for the determination of the masses and distances of 

 the heavenly bodies. The length of the pendulum 

 vibrating seconds of mean solar time in the latitude of 

 London, forms the standard of the British measure of 

 extension. Its approximate length oscillating in vacuo 

 at the temperature of 62 of Fahrenheit, and reduced 

 to the level of the sea (N. 150), was determined by 

 Captain Kater to be 39-1393 inches. The weight of a 

 cubic inch of water at the temperature of 62 of 

 Fahrenheit, barometer 30 inches, was also determined 

 in parts of the imperial troy pound, whence a standard 

 both of weight and capacity was deduced. The French 

 have adopted the metre equal to 3-2808992 English feet 

 for their unit of linear measure, which is the ten-mil- 

 lionth part of that quadrant of the meridian (N. 151), 

 passing through Formentera and Greenwich, the middle 

 of which is nearly in the forty-fifth degree of latitude. 

 Should the national standards of the two countries be 



