ASTRONOMICA. 193 



„ refrre those, to which the attention cf theprac» 

 „ tlcal irarincr oiight chitfly to be diiected." (1) 



„ To obtain ilie longitiidc of ar.y place several 

 y, ingenioiis artists have e.xerted thcir ab.litics, an.l 

 „ have broiight time-keepcrs to an astcnishing 

 „ degree of perfection , whereby thcy have beco- 

 „ nie a valiiab^e acquisition lo ihe navigator in de- 

 „ tcrmining the diflerence of longitiide niade in 

 „ short periods: huwever considcring the dclicacy 

 „ of iheir conscriiction , and ihe various accidents, 

 „ to which they are liable, an impHcir confidence 

 „ oiight not to be placed on theri, particnlarly ia 

 y, long voyages ; biit recoiirse shoiild be had to 

 „ astronomical observations wheneveropportunities 

 „ present themselves. . . . The raost practical me- 

 „ thod of finding the longitude at sea by celestial 

 „ observations,- is t.hat of measuring the angular 

 „ disiance beiween the moon and sun , or the moon 

 „ and certain stars near the ecliptic , usually called 

 „ a lunar observation.'" (2) 



„ From the mutual concurrence of the opinions 

 „ of so many eminent men it appears , that ihe 

 „ method of finding the longitude at sea by obser- 

 „ ving the distance between the moon and the 

 „ sun , or a fixed star , commonly called lunar 

 „ observations , is the best in use at present. . . . 



(i) Riddle, JXAutical Jstrcnomit. p. C40. 

 (j) Norie, PractJcal Aavigatiea. p. »21« 



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