65 
points I placed a little pin hole in thin brass, so that I could see the 
opposite point through it; and, instead of marking the paper with 
the points, I intersected a little square cube with a fine perpendicu. 
lar line marked on it, where the station to be determined was likely 
to come. I moved it back and forwards, till the protractor, when 
set to the division, showed where the line should be drawn, which I 
did without taking up the protractor. In this way I marked every 
station round, at once, from the angles in the field book. 
This may be called surveying on paper, as I made use of the 
protractor in laying down the angles, as [ had done the theodolite 
in the field. 
And when the paper was kept of equal dryness in the large tri- 
angles, I could perceive an error of a minute. 
I here give you a table of the angles to twenty seconds, and the 
sides calculated in feet, with the latitudes and longitudes of a few of 
the stations. 
I am, dear Sir, 
Your’s sincerely, 
WILLIAM EDGEWORTH. 
