( 158,1 ) ^ 
manifeft, that the fnftrumtnt lyeth exa£l]y in the Meri^ 
dian, fo as to lej^^any Star on the Meridian to the North. 
And that ymr may fee the fame Suutheily 5 the next day^ 
or^en yon pleafe,you may hang up the Plumb-line E. 
F. upon the Southern arm C D. fo as that the Plumb- 
line may exsdly interfeft the Perforation c. d. This 
may eafily be done by moving the top Joynt, with the 
Plumb-line on its Crofs piece backward and forward^ 
till the Plumb4ine hangeth to your mind. If the 5ight 
with the lefTer perforation a. b. be not exaSly under 
the Northern Plumb-line, it muft be brought to be fo by 
turning the Sight, by help of its Joynt at I. Andthen 
all the loftrument is fet right, foastofee the Sun, Moon 
or Stars come on the Meridian towards the South, 
But to fee the Sun tranfit the Meridian, it is neeeflary 
to guard the Eye, with a coloured Glafs, or a Glafs 
darkened with the fmoak of a Lamp or Candle. Which^ 
* for the fake of thofe who do not know the way of it, it 
may be necellary to defcribe. 
A Glafs to look ^ipon the Sum 
Chufe two pieces of Glafs cut into the (ame fee and 
figure. But take care they do not refraft. Which nnj- 
be known by moving the Glafs before the Eye. If the 
objefts you look on, feem to dance about, theCbfles are 
falfe and refradt 5 but true if all fecms fteady, Smoak 
one of thefe Glailes oyer the flame of a Lamp or Candle, 
until it be obfcured enough to take off the Sun- rays 
fufficiently, but not fo as to darken it too much. This 
may be feen by looking upon the Sun with it, or upon 
the Candle. One of the Glaffes being thus darkened, 
lodge them both together and faften thera m a little cafe - 
fit for the purpofe, vv'ith the fmoaked fide inriermcft, nnd 
an .edging of Card between, to keep the Gaiu : afundcrj 
fo as that the Soot may not be riibb'd off, or difordered. 
