of the Equatorial Instrument. 6g 
nomie fyfoderne, Tome I. p. 6 87 ; and a description of the as- 
trolabium armillare of Ptolemy, according to Regiomonta- 
nus's conception of it, who may be considered as the best com- 
mentator upon the Almagest now to be met with, will be 
found in Weidler’s Historia Astronotnix, quarto, 1741. 
(3.) The next autnor that presents himself is Copernicus, 
(who lived in 1530) and in his work De Revohitione Orbium 
ccelestium , lib. 2. c. 14. De exquirendis Stellar um Locis, pro- 
fessedly describes the same instrument with Ptolemy ; but, 
as it appears to me, something more complicated, having a 
greater number of circles, and in truth what in later times has 
been understood by the name, Armillary Sphere. 
(4.) After Copernicus, 1 find, in a work of Apian, who 
was his contemporary, or a little after him, viz. about 1538, a 
complete description of the torquetum , with all the parts of 
it minutely detailed, assisted by four or five wooden plates, 
together with the use of the instrument. This work, which 
is also very scarce, is in folio, intitled, Introductio geographica 
Petri Apiani in djctissimas Verneri Annotationes , &c. &c. cui 
recens jam opera P. Apiani accessit Torquetum , Instrumentum 
pulcherrimum sane et utilissimum . Ingolstadii , anno 1533. To- 
wards the conclusion of this work is a curious letter of Re- 
giomontanus to Cardinal Bessarion, De Compositione Me- 
teoroscopii, that is, the armillary sphere that was used by 
Ptolemy, with a plate of it. 
(5.) To Apian succeeded, at some distance, but exceeded all 
that went before him, the justly celebrated Tycho Brahe, 
who in his Astronomies Instauratce Me, hanica* Noribergce , 1602, 
* See also Hist . Coelestis , Lib . Prolegom . Tychonis Brahei, Augustes Viudeli - 
corum, 1666, II. Vol. folio, p. 118 and 119. 
