ASTRONOMY. 151 



d. This is only one of many methods that have been 

 contrived for the calculation of eclipses. LA 

 LANDE, Astron. torn. u. 1860, &c. 



e. The geometrical construction, by means of a pro- 

 jection, is sufficiently accurate for the prediction of 

 eclipses. The most simple is that which supposes 

 the observer to be placed in the sun, and to see the 

 path which any place on the earth's surface de- 

 scribes in consequence of the diurnal motion, pro- 

 jected into an ellipsis on the plane of the earth's 

 disk, while the path of the moon's shadow is pro- 

 jected into a straight line on the same disk. LA 

 CAILLE, Astron. VINCE, J 575. 



-y 



f. A very great addition to these methods of calcu- 

 lation was made by LA CAILLE, viz., that by which 

 a geographical representation is given of the path 

 of the shadow, the quantities and the times of ob- 

 scuration, &c. for all places of the earth. LA 

 CAILLE, Astron. 1 166. LA LANDE, Astron. 191 1. 



The construction of such a map may be made with 

 sufficient accuracy by means of a celestial globe. 



Number 



. 



