2$ 2 Mr. Nicholson’s Method oj\ See. 
be found on fuch lines of the arrangement as would have occu- 
pied the vacant places if the fucceffion of lines had been inde- 
finitely repeated tideways. 
I approve of this conflruclioti, as fuperior to every other 
•which has yet occurred to me, not only in point of conve- 
nience, but likewife in the probability of being better exe- 
cuted, becaufe fmall arcs may be graduated with very great 
accuracy, by divihons transferred from a larger original. The 
inftrument, fig. i . may be conveniently contained in a circle 
of about 4I inches diameter. 
The circular inflrument is a combination of the Gunter’s 
line and the fedtor, with the improvements here pointed out. 
The property of the fedlor may be ufeful in magnifying the 
differences of the logarithms in the upper part of the line of 
lines, the middle of the tangents, or the beginning of the 
verfed fines. It is even poffible, as mathematicians will eafily 
conceive, to draw fpirals on which graduations of parts, every 
where equal to each other, will Ihew the ratios of thofe lines 
by means of moveable radii fimilar to thofe in this inflrument. 
But I do not, in this Difcourfe, propofe to enter into enquiries 
refpe&ing the nature of fuch curves, nor their utility in th« 
$>relent bufinefs. 
