Improvement in the Quadrant of Altitude . 3 
apprehend, may be efteemed fufficient not only as a cb -ck 
upon numerical computation, but to come near enough to bid 
ftars in the day-time in the field of telcfcopes, which, h h. . 
no equatorial motion, are only capable of direction in alfti; 
and azimuth ; but from globes of a larger fizc, vve may expect 
to come proportionably nearer. 
Explanation of the figures , Plate I. 
The figures 1. and 2. being different views of the fame 
things, AB reprefents a line, in common to both, in the fur- 
face of the horizon, which here is of brafs. 
CD, CD, are vertical lines, fuppofed to pafs through the 
center of the globe in each figure ; and 
EFG, EFG, are portions of great circles of the globe. 
Fig. 1. fuppofes the fpedlator looking at the apparatus of 
the globe from the fouth point of the horizon ; therefore the 
circular arch EFG, in this pofition, will be a part of the 
prime vertical , and the fmall paralellogram HI is fuppofed to be 
a fedlion of the brafs meridian, according to that vertical plane. 
Fig. 2. is a view of the fame parts, the fpe&ator being 
fuppofed to look at them from the w r eft point of the horizon ; 
and in this pofition HI is fuppofed to be a portion of the brafs 
meridian. This being fixed in mind, in what follows the fame 
letters denote the lame parts in both figures. — KLM denotes 
a piece of brafs, or brafs carriage, made to fit upon the ver- 
tical part of the meridian, and capable of Aiding f on each 
fide of that point, fo as to adjuft to it, and to fix fall: there, by 
means of the finger ferew N *. This piece of brafs carries 
* The holes reprefented in the portion of the brafs meridian (HI, fig. 2.' are 
ferew holes at five degrees difiance, in this quarter of the circle, into any ot 
which the finger ferew N is to be put as occalion may require; the Jl t allowing 
fufficiently for a dj ulhnen t* 
B 2 the 
