122 Mr. de Mendoza y Rios on the principal , See. 
“ In order to avoid as much as possible the inconvenience 
arising from using negative quantities, or giving different cases, 
the table D is continued to 125 0 of apparent distance, and the 
numbers in the table A are increased by 0,0003, so as to make 
them always positive; and to compensate this, the numbers in 
D are increased by 0,0002, and those in the correction of 
by 0,0001. It was found proper also to give the table 
C for four different values of horizontal parallax. 
“ The above tables are short, and do not require proportional 
parts to be taken. The only part of the work in which this is 
wanted, is in finding the angle answering to the natural cosine 
of the true distance. In finding the natural .cosine of the ap- 
parent distance this is avoided, by neglecting the odd seconds 
in working the problem, and adding them to the result.” 
