C 242 ] 
for the Prince of Orange ; the other two I have ftill 
by me, one of which I (hall {hew to the Society. I 
do not pretend to any-thing new in the Combination 
of thefe Circles, of which this Inftrumcnt confifts, 
the fame Combination having feveral times been 
made before me, by way of a Dial: But I believe 
the putting fo large a Telefcope upon this Machinery, 
and applying it to the Ufes which I have done, is 
fome what new. I am, 
Sir, 
Surryjireet , 7 th Tour mo ft obedient humble Servant, 
Dec - J a. Short. 
‘ Defcription and Ufes of the Equatorial Telefcope , 
or Tor table Obfervatory. 
HIS Inftrument confifts of two circular Planes 
or Plates, mark’d AA in the annexed Drawing, 
Tab, III. which are fupported upon four Pillars; and 
thefe are again fupported upon a Crofs-foot,or Pedef- 
tal moveable at each End by the four Screws BBBB : 
The two circular Plates AA are moveable, the one 
above the other, and are called the horizontal Plates, 
as rcprefenting the Horizon of the Place ; and upon 
the upper one are placed two Spirit-Levels, to render 
them at all times horizontal : Thefe Levels are fixed 
at Right- Angles to one another: This upper Plate is 
moved by a Handle C, which is called the Horizon- 
tal Handle, and is divided into 360% and has a No- 
nius Index divided into every three Minutes, 
Above this horizontal Plate there is a Semicircle 
DD , divided into twice 90*} which is called the Me- 
ridian Semicircle, as reprcfenting the Meridian of the 
Place, 
