Cm] 
Mail 1 8. 5 P.il/. ' 
Diftantia Meriaiana Solis a Vertice 
30 0 04'. 
1 31 53 Limbus praecedens Veneris Meridian. 
tranfit. Centro diftant a Vertice 
2f° 57' if". 
Mercurium culminantem neque hac die 
videre licuit, coelo licet admodum * 
fereno. 
N. B. Diftantix a vertice a refradioni- :V 
bus non purgantur. 
Vide Fig. 2 ,\in Tab. 
XIII. ‘The Ufe of a new Azimuth Compafs 
for finding the Variation of the Compafs 
or Magnetic Needle at Sea , with greater 
Eafe and Exaffnefs than by any ever yet 
contriv’d for that Eurpofe 5 by Captain- 
Chriftopher Middleton, F. R. S» 
T O difcover the Declination of the Magnetic- 
Needle, or Variation of the Compafs at Sea, 
with fome tolerable Degree of Certainty and Exadf 
nefs 7 is a thing of great Ufe and Importance in the. 
Art of Navigation. 
The Inftruments and Methods hitherto ufed for 
this Purpofe, (as we could eafily demonftrate, if it 
were needful) are fubjed to feveral Inconveniencies, Er- 
rors and Defeds 5 to remedy which, this new Azimuth 
Com- 
