[ 38 9 ] 
XXXVI. A n ew Method of confruEling Sun - 
Dials, for any given Latitude , without 
the Ajjiflance of Dialing Scales or Lo- 
garithmic Calculations . By James Fer- 
gufon, F. R. S. 
Read July 2, | AR A W the flraight horizontal line 
1767 ; JJ BAD Tab. XVI. (fig. i.) of any 
convenient length, and on the end D thereof raile 
the perpendicular DE. 
BifeCt BAD at A, and draw the right line ACE, 
making the angle EAD equal to the latitude of the 
place for which the dial is to ferve, as fuppofe 51 0 4. 
for the latitude of London. Draw alfo the right line 
FC D, making an angle at D with the horizontal 
line BAD equal to the co-latitude of the place, or 
height of the equinoctial. So, FCD will be per- 
pendicular to ACE, BAD will be a horizontal 
plane feen edgewife, D E a vertical plane, FCD 
the plane of the equinoctial, and ACE the axis or 
ftile of the dial 3 the whole triangle ADE repre- 
fenting the whole broad plate or ftile. 
Around the interfeCtion C, as a center, with the 
radius CD, defcribe the circle F6D6F, and divide 
its circumference into 24 equal parts, beginning at 
D or at F. Then conned: all the points of divifion, 
which are equidiftant from F, by the flraight lines 
i ti, 2 10, 3 9, 4 8, &c. continuing as many of 
4 thefe 
