L l 9 ]

idu,>£ as the other two, is pretty evident from thesituation of the Nodes, its Perihelion and Inclinationwhich are not very different from the other two;but the imperfect observations made by him witha small azimuth instrument, whose only use was toshew the ascent of the Comet’s tail in the parts op-posite the Sun, render all attempts to reduce tholeobservations to accuracy ineffectual. However,that he would omit nothing, he with great troubleprocured Appiaris Book, intituled, AstronomiconCœsareum, dedicated’to the Emperor Charles V.

But as the Longitude of the six’d Stars werevery erroneously asiign’d at that Time to what theyare at present, if the true ones are substituted, aslikewise allowance made for the refractions, theplaces of that Comet were thus,

True place of Comet.

deg. min. fee.

August 13, 1531, Leo 20 16 o

23 Libra 3 .49 o

But according to Appier!% observations.

deg. min. sec.

August 13, 1531, Leo 19 15 o

23 iLiora i 23 o

Now tho’ Appiaris places of the Comet differfrom the true ones, on account of his using wrongLatitudes and Longitudes of the fixt Stars, and badinstruments; yet the differences are not equal inall, but greater in some, and less in others, whichshews they were not all equally accurate, for onthe 13th of August he differs but 1 degree, 1 mi-nute from the truth, but on the 23d of August hediffers from the true place 2 degrees 26 minutes,

C 2 so