C 474 ] 
The firfl term ^ will always give a near approximation 
to the value of fin. and IS being found the correction, 
J X vf. or cot. a x vf. jS, may be found and added to it. 
Among the tables requifite to be ufed with the Nautical 
Almanac, is table iv. for parallax, p. 19. which fhews 
the value at fight of fuch quantities as vf. ^ x cot. a, the 
arc IS being found in the firfl; column of the table, and 
a at the top. This table I have calculated only to arcs 
under 6 i but it would be found ufeful to have a table 
ready computed for all arcs under 5®^ 
P R CH 
