L A T 



The use of the first five columns is obvious : the column of reciprocal* 

 is useful for converting- a vulgar into a decimal fraction, as in the fol- 

 lowing example. 



Express ~ as a decimal. 



By Table -^ is .035714286 



JULIAN Period. See Cyrle. 

 JUNO. 



This planet was discovered by Mr Harding', at Lilienthal, September 

 1st, 180-1. For its elements, &c. see Planets, elements of. 



JUPITER. See Planets, element* of. 

 JUPITER'S Satellites.!^'*? Satellites. 



L 



LAND Surveying. See Surveying 1 . 

 LATITUDE Geographical. (Woodhouse. ) 



1st Method, by the Altitudes of circumpolar stars. 



Co-latitude half the sum of the greatest and least zenith distance* 

 corrected for refraction. 



Or the latitude may be found by Captain Kater's method, from an ob- 

 served altitude of the pole star when out of the meridian thus (Gal* 

 Iraith.) 



To the constant log. 5.3144-25, add the log-, tangent of the star's polar 

 distance p, and the log. cos. of the meridian distance t in degrees, the 

 sum of these will be log. of an arc u in seconds. Now to the log. secant 

 p add the log. cosine u t and cosine of the zenith distance z ; the sum will 

 be the cosine of ($ i w) an arc which being increased or diminished by 

 the arc w, will be the co-latitude $/. 



To find t, calculate the time of the star's meridian passage (see Time}, 

 f hf difference between which and the time of observation gives t. 



In the application of u attention must be paid to the sign of the arc t, 

 according to its situation in the circle which the star describes round tH 

 157 13 



