THE DISTANCES OF A COMET FROM THE EARTH. 115 



tan.* h" -\-, &c. This table therefore gives the logarithm of the co- 

 efficient, reducing -5 to H= 1 — ^ tan.^ /t + &c., H being the de- 

 velopment of the expression -1 ^Azzf^Li* when sin.^ h is negative ; 

 and is taken from Table II. vi^ith the argument log. tan." h. 



Table III. contains the logarithms of ^ in the parabola, with the 

 argument log. ttjv^I = log. a. (Vide Mem. of Berlin Acad, for 1778, 

 pp. 148, 150.) 



Table IV. contains the logarithms of j^ in the parabola, with 

 the argument log. ^qiTjyi . It is used in connection with (76). 



Table V. contains the logarithms of y" in the parabola, with 

 the argument log. (1 — q") and may be used with (89). 



Table VI. contains the corrections to be applied to the sun's 

 longitudes, as taken from the Nautical Almanac, to refer them 

 to the mean equinox of Jan. 1st of each year ; and may be used 

 in preparing the sun's places for computing the elements of a 

 comet. 



